In the steady state condition the rate of heat produced in a choke coil is `P`. The time constant of the choke coil is `tau`. If now the choke coil is short circuited, then the total head dissipated in the coil is

Options

A. `Ptau`
B. `1/2Ptau`
C. `(Ptau)/(ln2 )
D. `P tau ln 2`

Answer

B

Explanation

`P=i_0^2Rimplies i_0^2=P/Rimpliestau=L/R`
`:. L=tauR`
Heat dissipated `=1/2Li_0^2=1/2 (tauR)(P/R)=1/2Ptau`