Question

What will happen to a compass needle when the compass is placed below a wire and a current is made to flow through the wire ?
Give a reason to justify your answer.

Answer 1

The compass needle when placed below the current carrying conductor does not rest in geographic north-south position. It may rest in any other position.
The magnetic field produced by the conductor is at right to the direction of conductor. The compass needle now rests in the direction if resulting magnetic field due to conductor and of the earth.