Question

When the current is switched on through a wire,a compass needle kept nearby get deflected from its north-south position.Explain.

Answer 1

when a current is flown in the wire, a magnetic field is emited which we can find out by 'right hand thumb rule' . these magnetic field lines when comes near a compass needle the magnetic field makes to moves along it. the north south deflection of the compass needle is calculated by 'SNOW ' rule -when the compass needle is above the wire and the current is from North to south then the needle will deflect on west and when the current is reversed the needle will deflect in opposite direction.

Answer 2

Answer:

When current is passed through the coiled wire, it deflects the compass near it from its north-south position like a magnet. This is called magnetic effect of the current. As we know that needle of the compass is made up of a thin magnet. When this needle comes in contact with another magnet then the like poles of the magnet repel each other and opposite poles attract each other. So the deflection is seen in the needle. In this case the wire behaves like a magnet and causes deflection in needle of the compass.