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1. The problem statement, all variables and given/known data

An AC voltage of the form V = V_{max}sin 2*pi*f*t , with frequency 22 Hz and maximum voltage 763 V, is applied across a 17 W light bulb. When the voltage is first applied.

a) what is the current through the circuit?

Three Choices :

1. the maximum current

2. 0

3. the rms current

What is the correct answer and why ... ??

b) When t = T/4 , where T is the period of the applied voltage, what is the current in the circuit?

2. Relevant equations

P = I * V

I_{max}= [tex]\sqrt{}2[/tex] * I_{rms}

T = 1/f

3. The attempt at a solution

In part a) i think that when the voltage is first applied means that time is ZERO so it could be ZERO the options # 2

In part b) I substituted t = 0.25T or 0.25/f in this formual

V = Vmax sin 2*pi*f*t

I found V then I used P = I * V and solved for I but i got wrong answer.

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# Homework Help: The current in the circuit ?

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