CBSE Class 10 Answered

Prepare a circular coil (C) out of a copper wire.Connect the two ends of this coil to the two terminals of a sensitive galvanometer (G) with a scale having zero at the center. This ‘closed circuit’ is shown in figure. Note that this circuit contains no source of electricity and the galvanometer shows zero reading initially. Now, move the magnet ‘away’ from the coil. The galvanometer shows a deflection and the direction is noted.This means current is set up in this direction. 

 

In the above experiment of Faraday, when the bar magnet is moved w.r.t the coil, following observations were made:

i. Whenever there is a relative motion between the coil and the magnet, the galvanometer shows a sudden deflection. This deflection indicates the current is induced in the coil.

ii. The deflection is temporary. It lasts so long as relative motion between the coil and the magnet continues.

iii. The deflection is more when the magnet is moved faster and less when the magnet is moved slowly.

iv. The direction of deflection is reversed when the same pole of the magnet is moved in the opposite direction or opposite pole of magnet is moved in the same direction.