Question

1. Circuit A contains a battery, a switch, and a resistor connected in series. Circuit B contains a battery, a switch, an inductor, and a resistor connected in series. Initially, the switch is closed in both circuits. How does the behavior of the current in circuit B compare with that in circuit A as both switches are opened at the same time?

a. The current in circuit B decreases more slowly than that for circuit A since the inductor acts to maintain the current in the circuit.

b. The behavior of the current in the circuit depends on the inductance of the inductor. If the inductance is small, the current will decrease rapidly; and if the inductance is large, the current will increase for a short time before decreasing.

c. The current in circuit B decreases more quickly than that for circuit A since the inductor increases the current in the circuit as its stored energy is released.

d. The current in both circuits decreases at the same rate because inductors do not affect the current in a circuit.

Answer 1

Correct option is (a). An inductor consist of loops of wires, so that, when current through the inductor or loops change, it results in to an induced emf which always opposes its cause by Lenz's law. When the switch is opened the current through the circuit A quickly decreases to zero but in circuit B the inductor opposes this decrease of current in the circuit and current slowly decreases to zero (exponential behavoir).