In the figure, an ac generator with emf E = E m sin ? d t , where E m = 24.9 V a
ID: 1296984 • Letter: I
Question
In the figure, an ac generator with emf E = Em sin ?dt, where Em = 24.9 V and ?d = 382 rad/s, is connected to a 4.38 ?F capacitor. (a) What is the maximum value of the current (in A)? (b) When the current is a maximum, what is the emf (in V) of the generator? (c) When the emf of the generator is - 12.1 V and increasing in magnitude, what is the current (in A)?
In the figure, an ac generator with emf E = Em sin ?dt, where Em = 24.9 V and ?d = 382 rad/s, is connected to a 4.38 ?F capacitor. (a) What is the maximum value of the current (in A)? (b) When the current is a maximum, what is the emf (in V) of the generator? (c) When the emf of the generator is - 12.1 V and increasing in magnitude, what is the current (in A)?Explanation / Answer
a)
Capacitive reactance X_C = 1 / 2 pi f C = ( 382 rad /s ) (4.30* 10 ^ -6 F ) = 608.79 ohm
b)
Maximum value of current
I = V / Z = 24.9 V /608.79 ohm = 0.04 A
c)
Emf of the generator at maximum current
emf = ( 0.04 A)(608.79 ohm) = 24.9 V
d)
V = emf + I r
I = 24.9 - 12.1 / 608.79 = 0.021 A