physics answer n9 08
TRANSCRIPT
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JPNS SPM TRIAL 2008
Answer P1 (Physics Paper 1)
1 A 11 C 21 B 31 B 41 B
2 D 12 C 22 C 32 A/B 42 C
3 D 13 D 23 B 33 A 43 A
4 D 14 C 24 C 34 A 44 A
5 C 15 C 25 Bonus 35 B 45 A
6 B 16 D 26 A 36 A 46 C
7 A 17 C 27 D 37 A 47 C
8 C 18 B 28 C 38 C 48 B
9 D 19 B 29 A 39 A 49 A
10 B 20 D 30 D 40 B 50 B
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TRIAL JPNS PHYSICS ANSWER PAPER 2
SECTION A
Question
Number
Answer Full
Mark1.(a) (i) base quantity is a quantity that cannot be defined in any other physical
quantity
1
(ii) ms-2
1
(b) Base quantity - time / displacement
Derived quantity - velocity / accelerationScalar quantity time
Vector quantity - displacement / acceleration
1
1
Total 4
Question
Number
Answer Full
Mark
2.(a) Convex mirror 1
(b) Convex mirror has a wider view than a plane mirror. 1
(c)(i)
Note :
Draw two incident rays and each of them reflected at thecorrect path.
1 mark
Shows image formed behind the mirror and the position infront of F.
1 mark
2
(ii) Virtual ,upright and diminished. (any of two combination) 1
Total 5
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Question
Number
Answer Full
Mark
3(a) Step-down transformer 1
(b) A.u. power supply, Vp can produce a changing magnetic field thatinduces an alternating e.m.f in the secondary coil, Vs.
1
(c) Using a formula , Np = VpNs Vs
Np = 240V
Ns 12V
Np : Ns = 20 : 1
1
1
(d)(i) Bulb will not light up 1
(ii) Because transformer cannot function using direct current/cannot produce change in magnetic flux
1
Total 6
Question
Number
Answer Full
Mark
4(a) W = mg= (50)(10)
= 500 N 1
(b)(i) Increase 1
(ii) Decrease 1
(iii) Stationary / at 500N 1
(c) No resultant force/acceleration zero 1
(d) R = (46)(10)
= 460 Nmg-R = ma
500 460 = 50a
a = 0.8 ms-2
1
1
Total 7
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Question
Number
Answer Full
Mark
5(a) Quantity of heat required to increase the temperature of 1 kg of material
through a temperature of 1oC
2
(b) (i) Energy output = power x time
= 3 x 103
x 3.5 x 60= 6.3 x 10
5J with unit
11
(ii) Energy required to raise the temperature of water,
Q = mc= 1.7 x 4.2 x103 x (100 -20)
= 5.71 x 105
J with unit
1
1
(iii) Energy required to boil away water,Q = ml
= 0.23 x 2.3 x 105
= 5.29 x 105
J with unit
1
1
Total 8
Question
Number
Answer Full
Mark
6 (a)(i) An electromagnetic waves is the vibration of electric and magnetic field 1
(ii) Can travel through vacuum
Speed of light
Transverse waves(any one answer)
1
(b) P : X-ray
Application : Radiotherapy for the treatment of cancerS : Microwaves
Application : Waves received by telephone and television signals from
satellite
1
11
1
(c) = v/f= 3x 10
8
3.2 x 103
= 9.375x104m
1
1
Total 8
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Question
Number
Answer Full
Mark
7(a)(i) Function for safety purpose/To ensure the maximum weight limit 1
(ii) F = mg= 7500 x 10= 7.5 x 104 N
11
(iii) The mark should be higher than the sea water level 1
(iv) 1. density of sea water is denser than the density of river water.
2. the volume of water displaced increased when density of liquid decrease
2
(b)(i) Upthrust = Weight 1
(ii) Accelerates upwards or moves upwards 1
(iii) 1. the weight of the air balloon is decreased2. buoyant force /upthrust higher than weight
3. the balloon experiences the unbalanced force.(any two answers)
2
Total 10
Question
Number
Answer Full
Mark
8(a) (i) npn transistor 1
(ii) as a switch/automatic switchamplifier
11
(b) to limit the current to the transistor 1
(c)( i) VP increaseBecause resistance at P is higher
11
(ii) the transistor will switch on the relay switch
Ib will flow through the transistor and Ic will increase
1
1
(d) 10,000 x 6 = 2
10,000+ S
Resistance, S = 20 000 OR
RS = VS1000 + RS 6
RS = 20 000
1
1
(e) The bulb will not light upbecause it needs higher voltage/current to light up.
11
Total 12
SECTION B
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Question
Number
Answer Full
Mark
9 (a) (i) Temperature is a measurement of the average kinetic energy of the atoms or
molecules in the substance.
OrTemperature is a measurement of degree of hotness of an object.
1
(ii) 1. The kettle is hotter than the ice block / The ice block is colder than the kettle.
2. The hand feels hot when it touches the hot kettle / The hand feels cold whenit touches the ice block.
3. Diagram 9.1 shows heat flows from the kettle towards the hand whileDiagram 9.2 shows the heat flows from the hand towards the ice.
4. The heat will flow from a hotter object towards a colder object.
1
1
1
1
(b) 1. Sea has higher specific heat capacity than land.
2. The temperature of the sea increases slower than of the land.
3. The air above the land is warmer than the air above the sea /Density of air above the land is lower than the density of air above the sea.
4. The warm air above the land rises up.
5. Air from the sea moves towards the land.
1
1
1
1
1
Modification Explanation
1.Use the fluorescent lamp not
a filament bulb
Fluorescent lamp use less power and
economic (consume less power) compare
to filament bulb
2. Bigger cover with white
colour
Less reflection on eyes and absorb less
heat energy and good heat reflector
3. Use the adjustable stand
Or portable
The height of the lamp can be adjusted
Can be used anywhere
4. Connect with the earth wire Avoid short circuit and damage on thebulb
5. Use an energy saver lamp Produce same brightness with less powerconsumption
2
2
2
2
2
Total 20
Question Answer Full
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Number Mark
10(a)(i)
1. Bulbs are connected in parallel 1m
2. Switch and battery are connected in series 1m
3. Correct symbols for all components 1m
3
(ii) When the bulb is connected to a power supply of 1.5V, it will produce 3J of
energy in 1 second.
1
(iii) The brightness of bulb A is the same as bulb B 1
(iv) I = P/V
= 6/1.5= 4A
11
(v) Energy = Pt= 6 x 3600
= 21 600 J
OrEnergy = VIt
= 1.5 x 4 x 3600
= 21 600 J
1
1
(b)
Modification Explanation
Resistance of wire is low to prevent power loss due to heat
Melting point is high to prevent the wire from melting
Density wire is low to reduce the mass of wire / too heavy
Rate of rusting is low to prevent it from rusting easily
Rate of expansion of wire to prevent lengthening of wire
22
2
22
Total 20
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Question
Number
Answer Full
Mark
11(a) Pressure is defined as the force acting normally per unit area/
Pressure = Force
Area
(b) 1. When the small piston is pulled up, the hydraulic oil is drawn from thereservoir into the small piston
2. When the small piston is pushed down , the hydraulic oil is exerted with
force and experienced a pressure
3. The pressure is transmitted uniformly from the small piston to the bigpiston.
4. The forced produced raised the big piston / The system can convert a small
input force into a bigger output force.
(c)Characteristics Reason
Has higher boiling point So that liquid not easily boiling/
Has higher specific heat capacity So that it cant be easily become hot
Has lower density So the hydraulic jack is not heavy
Has lower rate of vaporisation Volume of liquid will not easily vaporise
Liquid L is chosen Reasons: L has higher boiling point, higherspecific heat capacity, lower density and
lower rate of vaporisation
2
2
2
2
2
(d) (i) Weight = mass x acceleration of gravityW = mg
W = 60 x 10
W = 600 N
1
1
(ii) Pressure = Force
Area
A = F = 600 NP 500 Pa
= 1.2 m2
Minimum area of each snow shoe = 1.2 = 0.6 m2
2
1
1
1
Total 20
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Question
Number
Answer Full
Mark
12(a) Reflection of waves 1
(b) (i)
(any two comparisons)
Radio waves Sound waves
Transverse waves Longitudinal waves
Can travel without medium Needs medium to travel
Have long wavelength Have short wavelength
2
(ii) The distance between the water molecules is closer compared to air molecules.Thus, the sound energy can be transferred faster.
11
(c) Characteristics Reason
Type of waves - longitudinal Because sonar is a sound waves
which is a longitudinal wave
High frequency Has high energy / can penetrate
deeper into the sea
High speed Can travel faster
High penetrating power Can penetrate through medium easily
The most suitable waves is S Because the waves is longitudinal ,
high frequency , high penetrating
power and has high speed.
2
2
2
2
2
(d)(i) d = vt2
= 1500 x1
2x 15= 50 m
1
1
(ii) To detect the depth of seabedTo detect the position of crude oil or sunken ship
To detect the condition of baby in the womb.Any two answers
2
Total 20
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PHYSICS : ANSWER PAPER 3
Question
Number
Answer Full
Mark
1(a) i. Real depth,H 1
ii. Apparent depth,h 1iii.Optical density of glass block
or Refractive index of glass blockor Type of medium
1
(b) Tabulate H and h and show H as the manipulated variable and h asthe responding variable.
H/cm h/cm
2.0 1.3
3.0 2.0
4.0 2.75.0 3.3
6.0 4.0
Give one (1) mark for each of the following :1. Show column for H and h respectively.
2. State the unit for H and h correctly.
3. State the value H up to 1 d.p4. Show the reading of h correctly up to 1 d.p
5. Show consistency of all data up to 1 d.p.
5
(c) Draw a graph of h against H
Give one (1) mark for each of the following :
1. Show h at y-axis and H at x-axis.
2. State the correct unit for both axis.
3. Show uniform scale for both axis.4. Show all data plotted correctly: 5 correct 2m
3-4 correct 1m
5. Draw a smooth and best fit straight line on the graph.6. The minimum size of the graph at least 5 x 4 squares (10
cm x 8 cm) starting from the first point to the last point.
7
(d) i. State the relationship between h and H correctly.(Based on the students graph) 1
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h is directly proportional to H
TOTAL 16
Question
Number
Answer Full
Mark
2 (a)(i) Show the extrapolation on the graph1
R is directly propotional toA
11
(ii) Show on the graph R = 1.6 1
When R = 1.6 ,A
1= 0.90 mm
-2 1
Hence, A = 1.1 mm2 1
(iii) Gradient of the graph
- draw triangle on graph1
= 1.8 01.02 - 0
= 1.76 mm2
1
1
(b)(i)R =
A
l
Hence, resistivity = gradient
l
= 1.76 mm2
150 mm
= 1.17 x 10-2 mm
OR = 1.17 x 10-5
m
1
1
1
(vii) -Use small value of current to avoid the wire from
getting too hot easily/-Make sure the all the connections all the tightly
connected/
-Switch off the circuit if no reading is taken to avoidwire from getting too hot
1
TOTAL 12
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Question
Number
Answer Full
Mark
3 (a) The volume of the snack pack influenced by / effected by / depends
on the atmospheric pressure of the surrounding. 1
(b) For a fixed mass and at constant temperature of a gas, its volume
will increase when the pressure decreases.
orThe volume of a gas increases when the pressure decreases.
1
(c)(i) To investigate the relationship between the volume and thepressure of a gas at fixed mass and temperature.
1
(ii) Manipulated variable :Volume of a gas, V
Responding variable :Gas pressure,P
Constant variable :Gas temperature,T / mass of a gas,m
1
1
(iii) Bourdon gauge, a syringe with volume scale and rubber tube 1
(iv)
1
(v)
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1. The piston of the syringe is pressed down slowly until the volume
of air inside is 120 cm3.
2. The pressure of the air in the syringe is read from the Bourdon
gauge.
3. The experiment is repeated with volume of air inside the syringeat 100 cm3, 80 cm3 , 60 cm3 , 40 cm3 and 20 cm3.
1
1
1
(vi) Volume , V / cm3 Pressure , P /Pa
120
100
80
60
40
20
1
(vii)1
TOTAL 12
Question
Number
Answer Full
Mark
4 (a) The strength of the magnetic field depends on the current flows in
the wire.
1
(b) The greater the magnitude of current, the stronger the magnetic
field.
1
(c) (i) To investigate the relationship between the current flows in the wire
and the strength of the magnetic field of an electromagnet.
1
Volume, V/cm3
Pressure, P/Pa
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(ii) Manipulated variable : the current in the solenoid
Responding variable : the strength of the magnetic field.
Fixed variable : number of turns of coils/the type of
core used/distance between the endof the soft iron rod and pins in
the petri dish.
.
1
1
(iii) D.C power supply, ammeter, rheostat, petri dish, retort stand with
clamp, a box of pins, soft iron rod, insulated copper wire andconnecting wires.
1
(iv) Set up the apparatus as shown in the figure.
1
(v) Start the experiment with 0.2A of current. Turn on the switch. Bringthe Petri dish of drawing pins near the lower end of the rod.
1
(vi) Count the number of pins attracted to the rod. Turn the switch offthe to allow the pins to fall back into the petri dish.
Repeat the experiment by varying the current with 0.3A, 0.4A, 0.5A
and 0,6A.
1
1
(vii)Current/A Number of pins attracted
0.2
0.30.4
0.5
0.6
1
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(viii)
1
TOTAL 12
Number of pins attracted
Current