Question

A sinusoidal voltage V_osinωt is applied across a series combination of resistance R and inductor L. The amplitude of the current in the circuit is

• A. $\frac{V_{o}}{\sqrt{R^{2} + \omega^{2}L^{2}}}$
• B. $\frac{V_{o}}{\sqrt{R^{2} - \omega^{2}L^{2}}}$
• C. $\frac{V_{o}}{\sqrt{R^{2} + \omega^{2}L^{2}}}$sinωt
• D. V_o/R

Answer 1

Answer: (A)

$\frac{V_{o}}{\sqrt{R^{2} + \omega^{2}L^{2}}}$

Answer 2

Impedance of the circuit = $\sqrt{R^{2} + \omega^{2}L^{2}}$

Amplitude of voltage = V_o

∴ Amplitude of current = $\frac{V_{o}}{\sqrt{R^{2} + \omega^{2}L^{2}}}$,

Hence (1) is correct.