A 400-Ω resistor and a capacitor are connected in parallel across a 300-Hz source.If the amplitude of the current in the resistor is equal to that in the capacitor,what is the value of the capacitance?
A)1.33 μF
B)0.750 μF
C)10.6 μF
D)0.212 F

Question

Quizplus · Accepted Answer

The amplitude of the current in the resistor (I_R) is given by I_R = V/R, and the amplitude of the current in the capacitor (I_C) is given by I_C = VωC, where V is the voltage across the resistor and capacitor, ω is the angular frequency (ω = 2πf, with f being the frequency), and C is the capacitance. Given that I_R = I_C, we can set the two expressions equal to each other and solve for C: V/R = VωC => C = 1/(Rω) = 1/(400*2π*300) ≈ 1.33 μF.

A 400-Ω Resistor and a Capacitor Are Connected in Parallel