Question

A bar magnet is moved into a coil of insulated copper wire connected to a centre-zero galvanometer, as shown in the figure below.

1. Show on the diagram the direction of induced current in the coil.
2. State and explain clearly what is observed on the galvanometer when the S-pole of the magnet is moved into and then withdrawn from the coil.

Answer 1

1. 
   
2.    
   • S-Pole of magnet moved into the coil.
     -Galvanometer deflects to the left (on one side) momentarily. -Induced current in the coil flows so as to form a South Pole at the  end of the coil near the magnet.
   • S-Pole of magnet withdrawn.
     -Changing the direction of motion  reverses the direction of induced  current so that the end of the coil tends to form a N-Pole so as to oppose the motion of the magnet out of the coil.--Galvanometer reverses its direction of deflection/deflects to the right  momentarily.