An inductor coil stores U energy when i` current is passed through it and dissipates energy at the rate of P. The time constant of the circuit, when this coil is connected across a battery of zero internal resistance is

Options

A. `(4U)/P`
B. `U/P`
C. `(2U)/P`
D. `(2P)/U`

Answer

C

Explanation

`U=1/2Ll^(2) rArr P=I^(2)R` or `(2U)/P=L/R=tau`.