First slide
Magnetic flux and induced emf
Question

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 IP flows in P (as seen by E) and an induced current lQ1 flows in Q. The switch remains closed for a long time. When S is opened, a current IQ2 flows in Q. Then the directions of IQ1 and IQ2 (as seen by E) are

Easy
Solution

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. IQ1 will flow
in such a direction so that the magnetic field lines due to IQ1 passes from left to right through Q. This is possible when IQ1 flows in anticlockwise direction as seen by E. Opposite is the case when switch S is opened i.e. IQ2 will be clockwise as seen by E

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App