A 120-V rms voltage at 60 Hz is applied across an inductor and a 200-Ω resistor. If the impedance of this circuit is 216 Ω, what is the rms value of the current?
A) 0.336 A
B) 0.446 A
C) 0.556 A
D) 0.667 A
E) 0.767 A

Question

Quizplus · Accepted Answer

Using the formula for impedance in a series circuit:

Z = √(R^2 + X_L^2)

where R is the resistance, X_L is the inductive reactance, and Z is the impedance.

We can rearrange the formula to solve for the inductive reactance:

X_L = √(Z^2 - R^2)

X_L = √(216Ω^2 - 200Ω^2)

X_L = √(256Ω^2)

X_L = 256Ω

Now we can use Ohm's Law to solve for the current:

I = V / Z

I = 120V / 216Ω

I = 0.556A

Therefore, the answer is choice C.

A 120-V Rms Voltage at 60 Hz Is Applied Across