Question Detail

PHY 102 Last Minute Prep Objective Question

Question

The apparent power in an R-L circuit is 30VA. Source 36V, 50Hz, resistor 40Ω. Determine the inductance.
Options
A 1.05H
B 1.1mH
C 0.105H
Correct Answer
D 1.00H
Correct Answer

Option C is the correct answer.

Detailed Explanation

I = S/V = 30/36 = 0.833A. Z = V/I = 43.2Ω. X_L = √(Z² - R²) = √(1866 - 1600) = 16.33Ω. L = X_L/(2πf) = 16.33/(2π×50) = 0.052H.

Hint

Find impedance, then inductive reactance, then inductance.

Question Info