Question

A compass needle is placed near a current carrying wire. State your observation for the following cases, and give reason for the same in each case :

(i) Magnitude of electric current in the wire is increased.

(ii) The compass needle is displaced away from the wire.

Answer 1

(i) Deflection of compass needle increases. 

Magnetic field strength is directly proportional to the amount of current.

(ii) Deflection of the compass needle decreases.

Magnetic field strength is inversely proportional to the distance from the wire.