chapter 27: current & resistance - srjcsrjcstaff.santarosa.edu/~lwillia2/42/42ch27.pdf · •...

Chapter 27 Current amp Resistance

Current Dead or Alive DEATH bull NEUROLOGIC CRITERIA An individual with

irreversible cessation of all brain function including the brain stem is dead

bull CARDIOPULMONARY CRITERIA An individual with irreversible cessation of circulatory and respiratory function is dead

Positive Charges move from HI to LOW potential

HI V LOW V

Negative Charges move from LOW to HI potential

HI V LOW V

HOW FAST DO ELECTRONS MOVE IN A CURRENT

CARRYING CONDUCTING WIRE

Electron Speed is called the DRIFT Velocity

Drift velocity ~ 001 ms

Electric Fields travel at the speed of light

d

qEv

mv = pm=Ftm = qEtm

bull Current flows from a higher potential to a

lower potential (electrons flow the opposite

way) Current carrying wires are neutral

bull DC current flows in one direction

bull AC current oscillates back and forth

bull Electrons have a drift velocity of 001ms

bull Electric Fields travel at speed of light

I = Coulombsecond = Ampere

Current dQI

dt

Engine Current Problem

The starter motor of a car engine draws a current of 150 A from the battery The copper wire to the motor is 50 mm in diameter and 12 m long The starter motor runs for 080 s until the car engine starts

a How much charge passes through the starter motor

(a) Current is defined as I = Qt so the

charge delivered in time t is

Q = It = (150 A)(080 s) = 120 C

Current is charge in motion

bull Charge eg electrons exists in conductors with a

number density ne (ne approx 1029 m-3)

bull Current density J is given by J = qenevd = qnv

ndash unit of J is Cm2sec or Am2 (A equiv Ampere) and 1A equiv 1Cs

ndash current I is J times cross sectional area I = J pr2

ndash for 10 Amp in 1mm x 1mm area J = 10+7 Am2 and ve is about 10-3

ms (Yes the average velocity is only 1mms)

d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A

Engine Current Problem Again



b What is the drift speed of the electrons Show how the units work out

28 3electron number density 85 10 m

4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A

Fuses If the current drawn exceeds safe levels the fuse melts and the

circuit lsquobreaksrdquo ndash most house have switches not fuses

Fuse Problem You need to design a 10 A fuse that lsquoblowsrsquo if the current exceeds 10 A The fuse material in your stockroom melts at a current density of 500 Acm2 What diameter wire of

this material will do the job

J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model

bull E-field in conductor provided by a battery

bull Charges are put in motion but scatter in a very short

time from things that get in the way

ndash itrsquos crowded inside that metal

ndash defects lattice vibrations (phonons) etc

bull Typical scattering time = 10-14 sec

bull Charges ballistically accelerated for this time and then

randomly scattered

bull Average velocity attained in this time is v = Ftm = qEm

bull Current density is J = qnv so current is proportional to E

which is proportional to Voltage

bull OHMrsquos LAW J = s E s = conductivity

2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity

where E = electric field and

J = current density in conductor

L A

E

j

Property of bulk matter related to resistance of a sample is the resistivity (r) defined as

Jr

E 1r

s

eg for a copper wire r ~ 10-8 W-m 1mm radius 1 m long then R 01W

for glass r ~ 10+12 W-m for semiconductors r ~ 1 W-m

So in fact we can compute the resistance if we know a bit about the material and YES the property belongs to the material

For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es

bull The LONGER the wire the GREATER the R

bull The THINNER the wire the GREATER the R

bull The HOTTER the wire the GREATER the R

Resistance Resistivity

A

LR r

The HOTTER the wire the GREATER the R

Resistance Dependence on

Temperature

0(1 )R R T

0 original resistance

temperature coefficient of resistivity

temperature change (lt100 C)

R

T

When are light bulbs more likely

to blow

When hot or cold

0(1 )R R T


At lower Resistance the bulb draws more

current and it blows the filament

Resistivity Values



c What is the resistance in the copper wire

8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem

If the magnitude of the drift velocity of free electrons in a

copper wire is 784 times 10^ ndash4 ms what is the electric field

in the conductor The number density for copper is

849 times 10^28 electronsm3 What is the collision time

0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W

A rod is made of two materials The figure is not drawn to scale Each conductor has a square cross section 300 mm on a side The first material has a resistivity of 400 times 10ndash3 Ω middot m and is 250 cm long while the second material has a resistivity of 600 times 10ndash3 Ω middot m and is 400 cm long What is the resistance between the ends of the rod

Radial Resistance of a Coaxial

Cable Leakage bull Assume the silicon

between the conductors to

be concentric elements of

thickness dr

bull The resistance of the

hollow cylinder of silicon

is

bull The total radial resistance

is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a

This is fairly high which is desirable since you want the current to

flow along the cable and not radially out of it

Resistors

Ohms Law J Es

V = IR

Resistance QUESTION

How much current will flow

through a lamp that has a

resistance of 60 Ohms when

12 Volts are impressed

across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow

Electrical Power bull As a charge moves from a to b the electric

potential energy of the system increases by QV The chemical energy in the battery must decrease by this same amount

bull As the charge moves through the resistor (c to d) the system loses this electric potential energy during collisions of the electrons with the atoms of the resistor

bull This energy is transformed into internal energy in the resistor as increased vibrational motion of the atoms in the resistor

bull The resistor emits thermal radiation which can

make it glow

U q V

dU dq V dqP V I V

dt dt dt

bull You pay for ENERGY not for ELECTRONS

bull Kilowatt-hour is the energy consumed in one

hour [kWh]=J NOT TIME Power x Time

POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V

If V = 120V What is I

USE P = IV=gt I = PV

Appliance _ Power Current (A)

Hair Dryer 1600 Watts

Electric Iron 1200 Watts

TV 100 Watts

Computer 45 Watts




Hair Dryer 1600 Watts 133 A

Electric Iron 1200 Watts 10 A

TV 100 Watts 83 A

Computer 45 Watts 38 A

Electric Bill

Cost to run for 1 hr

$05 per 1 kw-hr

Cost = Power x Time x Rate Appliance _ Power Cost______



TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr


Hair Dryer 1600 Watts $008

Electric Iron 1200 Watts $006

TV 100 Watts $0005

Computer 45 Watts $0003

QUESTION

The voltage and power on a light bulb read

ldquo120 V 60 Wrdquo How much current will flow

through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION

The power and voltage on a light bulb read

ldquo120 V 60 Wrdquo What is the resistance of the

filament (I = 5 A)

Hint USE OHMS LAW V = IR

R = VI = 120 V 5 A = 240 W

bull The voltage of each device is the

full voltage of the EMF source

(the battery)

bull The total current is divided

between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R

Equivalent Resistance

bull The current is the same in each device

bull The equivalent resistance of the circuit is the sum

of the individual resistances R=R1+R2

Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R

To find the current use the total voltage and equivalent resistance

S

VI

R

Circuits ProblemBulbs in Series vs Parallel

A circuit contains a 48-V battery and two 240W light bulbs

In which circuit does each bulb burn brighter

RULE THE MORE POWER DISSIPATED IN A BULB THE

BRIGHTER IT IS

Find the power in each bulb when in series and in parallel

P IV

In Series

The Voltage is divided in series each bulb gets half V = 24V

2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel

Voltage is the same in each bulb 48V

2 2(48 )96

240

V VP W

R

W

Parallel Bulbs Burn Brighter

Circuits Problem3 Bulbs in Series

If one more bulb is added to each circuit

(3 bulbs total) how does the brightness

of the bulbs change Or not

In the series circuit the bulbs DIM WHY

22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V

In series each of the three equal bulbs gets one third of the Voltage

(V3) that a single bulb would get

Note P=VI but I is due to the equivalent Resistance I = VRs =V3R

So the Current through each is 13 the current through a single bulb and

P=VI=V3 x I3 = VI9 = P9 The bulbs burn 19 as bright

Circuits Problem3 Bulbs in Parallel




In the parallel circuit the bulbs DO NOT DIM

WHY

2

singlebulb

VP P

R

In parallel each of the three equal

bulbs gets the full voltage of the battery source

Is this getting something for nothing

NO Parallel circuits drain the battery faster

Parallel Circuits

bullAs the number of branches is increased the

overall resistance of the circuit is DECREASED

bullOverall resistance is lowered with each added

path between any two points of the circuit

bullThis means the overall resistance of the circuit is

less than the resistance of any one of the

branches (Weird)

bullAs overall resistance is lowered more current is

drawn This is how you blow fuses


If a bulb burns out - what happens to the other bulb in

each circuit Does it go out Is it brighter Dimmer Or

In the series circuit the burned out bulb will short the circuit and

the other bulb will go out

In the parallel circuit the other bulb will have the same brightness

QUESTION

The power rating for two light bulbs read

30W and 60W Which bulb has the greatest

resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W

Which burns brighter and why

Quick Quiz

For the two lightbulbs shown in this figure

rank the current values at the points from

greatest to least

Ia = Ib gt Ic = Id gt Ie = If

The 60 W bulb has the lowest

resistance and therefore draws the

most current and burns brightest

Resistance Question

bull The resistivity of both resistors is the same (r) bull Therefore the resistances are related as

1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr

bull The resistors have the same voltage across them therefore

1

12

28

1

8I

R

V

R

VI

bull Two cylindrical resistors R1 and R2 are made of identical material R2 has twice the length of R1 but half the radius of R1

ndash These resistors are then connected to a battery V as shown

V I1 I2

ndash What is the relation between I1 the current flowing in R1 and I2 the current flowing in R2

(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity

bull 1911 H K Onnes who had figured

out how to make liquid helium used it

to cool mercury to 42 K and looked at

its resistance

bull 1957 Bardeen (UIUC) Cooper and Schrieffer (ldquoBCSrdquo)

publish theoretical explanation for which they get the

Nobel prize in 1972

ndash It was Bardeenrsquos second Nobel prize (1956 ndash transistor)

ndashCurrent can flow even if E=0

ndashCurrent in superconducting rings can flow for years with no

decrease

bull At low temperatures the resistance of

some metals0 measured to be less

than 10-16bullρconductor (ie ρlt10-24 Ωm)

Superconductivity

bull 1986 ldquoHighrdquo temperature superconductors are

discovered (Tc=77K)

ndash Important because liquid nitrogen (77 K) is much cheaper than

liquid helium

ndash Highest critical temperature to date 138 K (-135˚ C = -211˚ F)

bull Today Superconducting loops are used to produce

ldquolosslessrdquo electromagnets (only need to cool them not

fight dissipation of current) for particle physics

[Fermilab accelerator IL]

bull The Future Smaller motors ldquolosslessrdquo power

transmission lines magnetic levitation trains

quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Current Dead or Alive DEATH bull NEUROLOGIC CRITERIA An individual with

irreversible cessation of all brain function including the brain stem is dead

bull CARDIOPULMONARY CRITERIA An individual with irreversible cessation of circulatory and respiratory function is dead


HI V LOW V


HI V LOW V






d

qEv

mv = pm=Ftm = qEtm









Current dQI

dt






Q = It = (150 A)(080 s) = 120 C









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers


HI V LOW V


HI V LOW V






d

qEv

mv = pm=Ftm = qEtm









Current dQI

dt






Q = It = (150 A)(080 s) = 120 C









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers


HI V LOW V






d

qEv

mv = pm=Ftm = qEtm









Current dQI

dt






Q = It = (150 A)(080 s) = 120 C









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






d

qEv

mv = pm=Ftm = qEtm









Current dQI

dt






Q = It = (150 A)(080 s) = 120 C









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers









Current dQI

dt






Q = It = (150 A)(080 s) = 120 C









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






Q = It = (150 A)(080 s) = 120 C









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers









d

qEv

mv = pm=Ftm = qEtm

IJ qnv

A






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






4

d 22 28 3 19

150 A5617 10 ms

00025 m 85 10 m 160 10 C

J I A Iv

nq ne r nep p

IJ qnv

A





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers





J I A

2

2

4 10 A40050 cm 050 mm

4 500 Acm

D I IA D

J J

p

p p

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Atomic Model








randomly scattered





2q n

m

s

d

qEv

m

IJ E qnv

As

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Resistivity



L A

E

j


Jr

E 1r

s




For uniform case IJ

A ELV

Jr r

I ρLV EL L L I

A A

A

LR rwhere IRV

2q n

m

s J Es





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers





A

LR r



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers



Temperature

0(1 )R R T




R

T


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers


to blow

When hot or cold

0(1 )R R T




Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Resistivity Values




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers




8 3

2 2

124 17 10 104 10

(005 )

4

l l mR x m x

DA mr r

pp

W W

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Problem





0181 V mE

IJ E qnv

As

qnvE qnvr

s

2q n

m

s

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

1 1 2 2 1 1 2 2

21 2

RA A d

r r r r

3 3

23

400 10 m 0250 m 600 10 m 0400 m378

300 10 m

R

W W W






thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers





thickness dr



is


is

2

ρdR dr

πrL

A

LR r

2ln

b

a

ρ bR dR

πL a



Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Resistors

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Ohms Law J Es

V = IR

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Resistance QUESTION





across it

USE OHMS LAW V = IR

12 122

60 60

V V VI A

R V A

W

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

What makes

the wires

Glow






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






make it glow

U q V

dU dq V dqP V I V

dt dt dt




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers




POWER

2V VP I V V

R R

WattEnergy J

Ptime s

2( )P I V I IR I R

P I V






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






TV 100 Watts

Computer 45 Watts






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






TV 100 Watts 83 A


Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Electric Bill


$05 per 1 kw-hr




TV 100 Watts

Computer 45 Watts

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Electric Bill


$05 per 1 kw-hr




TV 100 Watts $0005


QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

QUESTION



through the bulb

USE P = I V

I = PV = 60 W120 V = 12 Amp

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

QUESTION



filament (I = 5 A)


R = VI = 120 V 5 A = 240 W



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers



(the battery)


between each path

Parallel Circuits

1 2

1 2 1 2

1 1( )

P

V V VI I I V

R R R R R

1 2 3

1 1 1 1

PR R R R





Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers




Series Circuits

1 2 1 2 3+ SV V V R R R R

1 2 1 2 1 2( + ) + + I R R IR IR V V

total totalV IR




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers




Series Circuits

1 2 1 2 3+ SV V V R R R R


S

VI

R





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers





BRIGHTER IT IS


P IV

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

In Series


2 2(24 )24

240

V V VP IV V W

R R

W


In Parallel


2 2(48 )96

240

V VP W

R

W







22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






22 2

singlebulb 3 1

9 9

PVV VP

R R R

1 2 3V V V V











WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers






WHY

2

singlebulb

VP P

R





Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Parallel Circuits







branches (Weird)









QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers







QUESTION



resistance at 120V

2 2 P V R R V P

2(120 ) 30 480R V W W

2(120 ) 60 240R V W W


Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Quick Quiz



greatest to least





Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Resistance Question


1

1

1

1

1

2

22 88

)4(

2R

A

L

A

L

A

LR rrr


1

12

28

1

8I

R

V

R

VI



V I1 I2


(a) I1 lt I2 (b) I1 = I2 (c) I1 gt I2

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity




its resistance



Nobel prize in 1972




decrease




Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

Superconductivity


discovered (Tc=77K)


liquid helium








quantum computers

chapter 27: current & resistance - srjcsrjcstaff.santarosa.edu/~lwillia2/42/42ch27.pdf · •...

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