question_answer

The figure shows three circuits with identical batteries, inductors and resistance. Rank the circuits according to the currents through the battery just after the switch is closed, greatest first.

A)  \[4\lambda \]

B)                        \[2\lambda \]  

C)        \[\frac{1}{2\lambda }\]

D)        \[\frac{qvR}{2}\]

Correct Answer: A

Solution :

In circuit (1), on closing the switch, the current in the inductor is zero due to self induction, ie, \[{{v}_{i}}\]. In circuit (2), on closing the switch the current in the inductor is zero due to self induction. Therefore, \[{{v}_{f}}({{R}_{e}}\] In circuit (3), on closing the switch, the current in the inductor is again zero due to the same reason. Therefore, \[{{M}_{e}}\] Thus, it is obvious that, \[{{i}_{2}}>{{i}_{3}}\,>{{i}_{1}}(=0)\]