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

Why does a compass needle get deflected when brought near a bar magnet?

Arrange the following steps in sequential order to demonstrate the magnetic effect of the elctric cur-rent using magnetic compass. (A) Wind an insulated conducting wire around the magnetic compass such that the axis of the coil is directed along east west direction and con-nect the free ends of the wire to a cell through a switch. (B) Take a magnetic compass. (C ) When current flows through the conducting wire, it behaves as a magnet and deflects the compass needle. (D) When the switch is closed, the magnetic nee-dle in the compass deflects from its initial posi-tion and when the switch is opend, the needle comes back to its initial position.

When current is passed through a circular wire prepared from a conducting material, the magnetic field produced at its centre is B. Now a loop having two turns is prepared from the same wire and the same current is passed through it. The magnetic field at its centre will be :