A 35-$\mu$F capacitor is connected to an ac source of emf with a frequency of 250 Hz and a maximum emf of 20 V.If the voltage across the capacitor is zero at time t = 0, what is the voltage at time t = 3.0 ms? Assume the phase constant is zero.
A)−20 V
B)−10 V
C)0 V
D)10 V
E)20 V

Question

Quizplus · Accepted Answer

The voltage across a capacitor in an AC circuit is given by:$$V_c = V_{max} \sin(2\pi ft + \phi)$$where:* $V_c$ is the voltage across the capacitor* $V_{max}$ is the maximum voltage* $f$ is the frequency* $t$ is the time* $\phi$ is the phase constantIn this problem, we are given that:* $V_{max} = 20 V$* $f = 250 Hz$* $t = 3.0 ms = 0.003 s$* $\phi = 0$Substituting these values into the equation, we get:$$V_c = 20 V \sin(2\pi 	imes 250 Hz 	imes 0.003 s + 0)$$$$V_c = 20 V \sin(1.5\pi)$$$$V_c = -20 V$$Therefore, the voltage across the capacitor at time $t = 3.0 ms$ is -20 V.

A 35- μ\muμ F Capacitor Is Connected to an Ac Source of Emf

A 35- $\mu$ F Capacitor Is Connected to an Ac Source of Emf