Draw a labelled circuit diagram of a simple electric motor and explain its working. In what way these simple electric motors are different from commercial motors?
ABCD is a coil which is placed between the two poles of a permanent magnet. The coil is placed in such a way that the direction of current is perpendicular to the direction of magnetic field.
• Arms of the coil are attached to a split ring; which has two halves P and Q. Arms AB is attached to the half P, and arm CD is attached to the half Q.
• The split rings are touching two static brushes X and Y from which they get electricity supply. The split rings are insulated from inside. An axle is passing through the split rings.
• A battery supplies electric current to the coil. The flow of current is from A to B and C to D.
Working of Electric Motor:
Obeying Fleming’s Left Hand rule, when current passes from A to B; the arm AB of coil moves down. On the contrary, when current passes from C to D; the arm CD moves up.
When the coil makes half a turn, P of split ring touches brush Y and its opposite happens with Q of split ring. As a result, the direction of current gets reversed. This means current now flows D to C and from B to A. This pushes CD down and AB up. As a result, the coil turns continuously.
