(a) Consider the experimental set up shown in the figure. This jumping ring experiment is an outstanding demonstration of some simple laws of…

(i) Explanation of a jumping of ring

(ii) Explanation of outcome on changing terminals of battery

(iii) Explanation of two laws

OR

(b) Two ways to increase strength of magnetic field produced by solenoid - $\displaystyle 1$+$\displaystyle 1$

(i) The direction of induced current in the ring is such that the polarity developed in the ring is same as that of the polarity on the face of the coil, hence it will jump up due to repulsive force.

(ii) The polarity of the induced current in the ring will get reversed on changing the terminals of the battery, so the ring will jump again.

(iii) Lenz's law It states that the polarity of induced emf is such that it tends to produce a current which opposes the change in magnetic flux that produces it. Faraday's law of EMI Whenever there is change in magnetic flux through a coil, an emf is induced. The magnitude of the induced emf in a coil is equal to the time rate of change of magnetic flux through the coil.