Class 12-science NCERT Solutions Physics Chapter 6: Electromagnetic Induction
Electromagnetic Induction Exercise 174
Solution 1
Electromagnetic Induction Exercise 175
Solution 2
According to Lenz’s law, the direction of the induced current in a loop is such that it opposes the change in magnetic flux through the loop.
(a) In the case of a wire of irregular shape turning into a circular shape, the area of the loop increases with time. This results in an increase in magnetic flux through the loop. The induced current will produce a magnetic field in the opposite direction to oppose this change. Using the right-hand rule, we can determine that the current flows clockwise.
(b) In the case of a circular loop being deformed into a narrow straight wire, the area of the loop decreases with time. This results in a decrease in magnetic flux through the loop. The induced current will produce a magnetic field in the same direction as the initial magnetic field to oppose this change. Using the right-hand rule and following the path from point a to point d to point c to point b, we can determine that the current flows in the direction - adcb.