A coil of inductance `1 H` and resistance `10Omega` is connected to a resistanceless battery of emf `50 V` at time `t=0`. Calculate the ratio of rthe rate which magnetic energy is stored in the coil to the rate at which energy is supplied by the battery at `t=0.1s`.

Explanation

The required ratio `(E_("stored"))/(E_("supplied"))=(V^(2)//R)/(V_(0)^(2)//R)`
`=(V^(2))/(V_(0)^(2))=(V_(0)^(2)(1-e^(-t//tau)))/(V_(0)^(2))`
`=(1-e^(-t//tau))^(2)`
`=[1-e^(-((0.1xx10)/1))]^(2)`
`=0.36`