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

Options

A. `(V_(0))/(sqrt(R^(2) + (omega L)^(2)))`
B. `(V_(0))/(sqrt(R^(2) - (omega L)^(2)))`
C. `(V_(0))/(R + (omega L))`
D. `(V_(0))/(R)`

Answer

A

Explanation

(a) Imedance of series LR circuit can be written as follows :
`Z= sqrt(R^(2)+(omegaL)^(2))`
Amplitude of voltage is `V_(0)` . Hence amplitude of current can be written as follows :
`i_(0) = (V_(0))/( Z) = (V_(0))/(sqrt(R^(2)+(omegaL)^(2)))`