An ideal coil of `10` henry is joined in series with a resistance of `5` ohm and a battery of `5` volt. `2` second after joining, the current flowing in ampere in the circuit will be

Options

A. `e^(-1)`
B. `(1-e^(-1))`
C. (1-e)
D. e

Answer

B

Explanation

`i=i_(0)(1-e^((-t)/tau)),tau=L/R=10/5=2`
`rArri_(0)=5/5=1amp`
`rArr1(1-e^(-1))=(1-e^(-1))`.