Question

The diagram below shows a magnetic needle kept just below the conductor AB which is kept in North South direction.

1. In which direction will the needle deflect when the key _is closed?
2. Why is the deflection produced?
3. What will be the change in the deflection if the magnetic needle is taken just above the conductor AB?
4. Name one device which works on this principle.

Answer 1

1. East direction

2. When a magnetic field is applied, the needle will point in the same direction. Since the lines run perpendicular to the direction of the current, the needle will similarly attempt to align itself with that direction.

3. Because of this, the compass's north pole will point westward instead of north.
4. Electric motor.