Question

Give an illustration of determining direction of induced current by using Lenz’s law.

Answer 1

1. Move the bar magnet towards the solenoid with north pole pointing solenoid.
2. When the Magnetic flux increases in the coil, an induced current is produced, and the coil becomes a magnetic dipole.
3. According to Lenz law, induced current opposes the movement of the north pole towards coil.
   (a)
   
   (b)
   
   (c)
   
   
4. It is possible if end nearer to magnet becomes the north pole, then it repels the north pole of the magnet and oppose the movement of the magnet.
5. The direction of induced current is found by the right-hand thumb rule.
6. When a bar magnet is withdrawn, the nearer end becomes south pole which attracts the north pole of the bar magnet, opposing the receding motion of the magnet.
   7. Direction of induced current can be found from Lenz law.