A coil of inductance `300mh` and resistance `2Omega` is connected to a source of voltage `2V`. The current reaches half of its steady state value in

Options

A. 0.15 s
B. 0.3 s
C. 0.05 s
D. 0.1 s

Answer

D

Explanation

During growth of current in the coil
`i=i_(0)(1-e^(-Rt//L))`
For `i=(i_(0))/(2)`
`rArr" "(i_(0))/(2)=i_(0)(1-e^(-Rt//L))`
`therefore" "t=0.693(L)/(R)=0.693xx(300xx10^(-3))/(2)=0.1s`