alternating current - keeping it warm and fuzzy physikos 2009, [email protected]

11
Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, [email protected]

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Page 1: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

Alternating Current - Keeping it Warm and Fuzzy

Physikos 2009, [email protected]

Page 2: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

6V

1A

What does 6V mean?

What does 1A mean?

Lamp A

Page 3: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com
Page 4: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

• The flow over the Huka Falls fluctuates between 32 and 270 cubic metres per second. On average the daily flow over the falls is 160 cubic metres per second

Page 5: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

If there are 7 drops of water in 1cm3, how long would it take for

6,000,000,000,000,000,000 (6 million million million drops)

drops of water to flow over the Huka Falls?

(average flow rate = 160cubic metres per second)

Page 6: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

6,000 cubic metres/second

• Time for 6 million million million drops?

Page 7: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

6V

1A

Two lamps Identical to lamp A are placed in series

What is the brightness of lamp B compared with lamp A?

Lamp B Lamp C

a) B is the same brightness as A

b) B is half as bright as A

c) B is quarter as bright as A

Page 8: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

How many models do we need for electricity?

Page 9: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

LCR Circuit

VLVRVC

VS

Page 10: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

VL

VC

VR

VR is always in phase with current

I

VL leads current by 90˚

Page 11: Alternating Current - Keeping it Warm and Fuzzy Physikos 2009, steve.chrystall@gmail.com

0.01s

0.5A

Current vs time for previous LCR Circuit

Current (A)

Time (s)

If L= 20mH, calculate the Voltage at t=0s