A series L - R circuit is connected to a battery of emf V . If the circuit is switched on at t = 0 , then…

A series L-R circuit is connected to a battery of emf V. If the circuit is switched on at t=0, then the time at which the energy stored in the inductor reaches 1n times of its maximum value, is :
  1. LRlnnn-1
  2. LRlnn+1n-1
  3. LRlnnn+1 
  4. LRlnn-1n

Solution

Potential energy stored in inductor is given by U=12L2

∪∝l2

UU0=1I02

1n=1I02

1I0=1-e-RT/L=1n

t=LRlnnn-1  

Asked in: JEE Main 2020 (04 Sep Shift 2)

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