As shown in the figure, P and Q are two coaxial conducting loops separated by some distance. When the switch S is closed, a clockwise current `I_(P)` (as seen by E) and an induced current `I_(Q1)` flows in Q. The switch remains closed for a long time. when S is opened, a current `I_(Q2)` flows in Q. Then the direction `IQ_(1) and IQ_(2)` (as seen by E) are

Options

A. respectively clockwise and anti-clockwise
B. both clockwise
C. both anti-clockwise
D. respectively anti-clockwise and clockwise

Answer

D

Explanation

When switch S is closed magnetic field lines passing through Q increases in the direction from right to left.
So, according to Lenz's law, induced current in Q, i.e., `I_(Q_(1))` will flow in such a direction, so that the magnetic field lines due to `I_(Q_(1))` passes from left to right through Q. This is possible when `I_(Q_(1))` flows in anti-clockwise direction as seen by E. Opposite is the case when switch S is opened, i.e., `I_(Q_(2))` will be clockwise as seen by E.