In a student-made model of a simple electric motor
PHYSICS · Multi-part · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
In a student-made model of a simple electric motor, the split-ring commutator is accidentally replaced by a complete conducting ring. Brushes remain in contact with the ring as before.
(i) Explain the intended role of a split-ring commutator in a simple electric motor.
(ii) Describe what will happen to the rotation of the coil when a complete ring is used instead of a split ring. Give reason for your answer.
(iii) The motor sometimes stops after running for a while because one of the brushes loses firm contact with the ring. Explain how this fault affects the current direction in the coil and, consequently, the motion of the coil.