Question

In 1820, Hans Christian Oersted discovered that a magnetic needle is deflected by a current-carrying wire. For many years, he had expected to find a connection between electricity and magnetism. Before his discovery, Oersted had imagined the magnetic field to be a straight line along the direction of the wire - with the north pole at one end and the south pole at the other. This was a major reason why he took so long to discover electromagnetism. The figure below shows how Oersted would have arranged his wire and magnetic needle in his early experiments.

Ravi performed an experiment in his school laboratory to study the magnetic effect of electric current. He passed electric current through a straight copper conductor placed near a magnetic compass. He observed that the compass needle deflected when current flowed through the conductor. When the direction of current was reversed, the direction of deflection of the compass needle also reversed. Later, Ravi used a solenoid connected to a battery and placed a soft iron core inside it. He observed that the solenoid behaved like a bar magnet when current flowed through it and lost its magnetism when the current was switched off.

A compass needle placed under a current-carrying wire deflects towards the east. If the direction of current in the wire is reversed, the needle will

Assertion (A): An electromagnet loses most of its magnetism when the current is switched off. Reason (R): The magnetism of an electromagnet is produced by the electric current flowing through its coil.