Question

An inductive circuit contains resistance of 10 Ω and an inductance of 20 H. If an ac voltage of 120 V and frequency 60 Hz is applied to this circuit, the current would be nearly(a) 0.32 amp(b) 0.016 amp(c) 0.48 amp(d) 0.80 amp

Answer 1

answer : option (b) 0.016 amp

explanation : resistance of resistor , R = 10 Ω

inductance of inductor , $X_L$ = 20H

voltage of AC circuit , V = 120volts

frequency, $f$=60Hz

so, angular frequency, $\omega=2\pi f$ = 2 × π × 60 = 120π rad/s

now, current , $i=\frac{V}{\sqrt{R^2+\omega^2L^2}}$

= 120/√{10² + (120π)² × 20²}

= 120/√{100 + 14400π² × 400}

after solving this we get, i = 0.016 amp