HW _14 P2213 F09

# HW _14 P2213 F09 - power dissipated in it P(t(d Draw graphs...

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1 Physics 2213 Homework #14 Fall 2009 December 1, 2009 Do not hand in. However, materials covered in this homework will be included in the FINAL EXAM. Chapter 32 is not included in the FINAL EXAM. Read: Chapter 31 Exercises and Problems ( 6 problems ) : (1) #30.32 [Radio Tuning Circuit] (2) #30.57 [A Car Alarm] (3) [Household AC] The standard AC electrical outlets in our buildings are 120 V rms at a frequency of 60 Hz. (a) What are the angular frequency ω and voltage amplitude V max for this AC electricity? (b) If a light bulb of resistance 240 Ω is plugged into such an electrical outlet, what are the maximum electric current I max through the bulb and the maximum power P max dissipated in it? (c) If the instantaneous electric current through the bulb is given by i(t) = I max cos ω t, write expressions for the instantaneous voltage across the bulb v(t) and the instantaneous
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Unformatted text preview: power dissipated in it P(t). (d) Draw graphs showing i(t), v(t), and P(t) for 2 complete cycles of current oscillation. Arrange your graphs above one another with their time axes synchronized. (e) Using your graphs and results from part (c), show that the average power dissipated in the bulb P avg equals P max /2. What average power is dissipated in this light bulb? Show that this value can also be written as P avg = I rms 2 R = V rms 2 /R, where I rms = I max / 2 and V rms = V max / 2. (4) #31.39 [Europe vs USA] (5) #31.47 [LCR Series Circuit] Please add : What is the resonance frequency ? What happens to those quantities if the AC power frequency is at the resonance ? (6) #31.49 [High-Pass Filter]...
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## This note was uploaded on 12/25/2009 for the course PHYS 213 at Cornell.

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