Question

A battery is connected in series to an inductor and a resistor. After a long time, assuming the battery does not weaken, how is the current through the inductor changing?

Select One of the Following:

(a) The current through the inductor is approximately zero.

(b) The current through the inductor is approximately constant, but non-zero.

(c) The current through the inductor continues to increase at the rate it was increasing when the battery was first connected.

(d) The current through the inductor continues to decrease at the rate it was decreasing when the battery was first connected.

Answer 1

(b) option is the correct answer i.e. the current through the inductor is approximately zero but non zero , it is so because the induced emf across an inductor is given by - Ldi/dt , and we know that after a very long time , the current stops changing in circuit and hence di/dt becomes zero which gives a 0 induced emf across inductor. Therefore the current in the circuit becomes constant which is equal to V/R