Question

State what would happen to the direction of rotation of a motor if: the magnetic field were reserved.

Answer 1

Hint: To answer this question, one must know about the working and construction of an electric motor. As we know that the electric motor is a rotating device which converts the electrical energy to the mechanical energy and the principle involved that it is based on the fact that a current carrying coil experiences equal and opposite forces on the edges which rotates it continuously.

Complete answer:
An electric motor is a device consisting of a rectangular coil $ABCD$ which is made up of an insulated copper wire. The coil consists of a large number of turns and it is wound on a soft iron core. The coil is positioned between the two poles of a magnetic field, with the arms AB and CD perpendicular to the magnetic field's direction.

The ends of the coil are connected to the half two rings \[{R_1}\] and \[{R_2}\] called split rings. The inner sides of the split rings are insulated and attached to an axle. Two conducting stationary brushes which are usually made up of carbon are touched by the external cutting edges of ${R_1}$ and ${R_2}$ . So, when we reverse the direction of the magnetic field the direction of rotation is also reversed.

Note: It's worth noting that the electric motor works on the basis of magnetic force on a current-carrying wire. The direction of force is determined by the current flow and magnetic field directions. However, depending on the current flow, we can fix the magnetic field and create torque on a loop. Electric motors are built in this manner.