Inductors & DC Transients (Mixed)
In the circuit shown,

the switch S1 is closed at time t = 0 and the switch S2 is kept open. At some later time(t0), the switch S1 is opened and S2 is closed. The behavior of the current I as a function of time 't' is given by:
Show answer and solution
Answer: (a)
- S1 closed: the current grows as , a rising curve.
- At , S1 opens and S2 closes: L and R form a closed loop, so the current cannot jump; it decays exponentially as .
- Only graph (a) shows a smooth rise followed by an exponential decay (the others decay linearly or rise linearly).
- So the answer is (a).