A small electric motor is shown as a demonstration model in the school laboratory
PHYSICS · Multi-part · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A small electric motor is shown as a demonstration model in the school laboratory. When current is supplied, the rectangular coil starts rotating briskly in the magnetic field of the horseshoe magnet.
Answer the following with reference to the working of such a motor:
(a) Name the rule that helps you predict the direction in which each side of the coil will move when current flows through it.
(b) Explain, in not more than three sentences, how the forces acting on the two opposite sides of the coil make it rotate.
(c) State what form of energy is supplied to the motor and what forms of energy are obtained as output. Briefly describe the energy conversion taking place.
(d) The coil is wound on a soft-iron core. State two reasons why a soft-iron core is preferred.