A 120-V rms signal at 60 Hz is applied across a 30-mH inductor and a 100-Ω resistor. What is the rms value of the current in this circuit?
A) 0.80 A
B) 1.2 A
C) 1.4 A
D) 1.6 A
E) 1.8 A

Question

Quizplus · Accepted Answer

The impedance of the circuit is calculated using Z = √(R² + (XL)²), where XL = 2πfL. For f = 60 Hz and L = 30 mH, XL = 2π(60)(0.03) = 11.31 Ω. Thus, Z = √(100² + 11.31²) = 100.64 Ω. The rms current is I = V/Z = 120/100.64 = 1.2 A.

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