Question

A circuit contains a battery, a switch, an inductor, and a resistor connected in series. Initially, the switch is open.

At which of the following times does the energy stored in the inductor have the largest value?

A) before the switch is closed

B) immediately after the switch is closed

C) a long time after the switch is closed

D) none of the above

Answer 1

a long time after the switch is closed

Step-by-step explanation:

Energy stored in an inductor is given by

E = 1/2 L i²

A). Before the switch is closed the current in the circuit is zero so energy in inductor will be zero.

B). Inductor opposes the flow of current. It takes some time for current to reach its maximum value. So immedialtly after closing the switch the current and energy in inductor will still be zero.

C). After closing the switch it takes some time for current to reach its maximum value as inductor opposes the flow of current. so after a long time the current in inductor will reach its maximum value and hence the energy stored will be maximum.