Solve the Problem. -How Many Seconds After the Switch in an RL Circuit

Multiple Choice

Solve the problem.
-How many seconds after the switch in an RL circuit is closed will it take the current i to reach 20% of its steady state value? Express answer in terms of R and L and round coefficient to the nearest hundredth.

A) 0.22 L/R seconds
B) 1.81 L/R seconds
C) 1.61 L/R seconds
D) 0.42 L/R seconds