Electric Motor
An electric motor converts electrical energy into mechanical energy using the force on a current-carrying coil in a magnetic field, plus a commutator to keep it rotating in one direction.
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Principle of motor action
A current-carrying conductor in a magnetic field experiences a force. In a rectangular coil placed between the poles of a magnet, forces on opposite sides of the coil form a couple, creating a torque that makes the coil rotate. Fleming’s left-hand rule gives the direction of force on each side.
Role of commutator
In a simple DC motor, a split-ring commutator reverses the direction of current in the coil every half-rotation. This ensures that the torque on the coil always acts in roughly the same rotational direction, allowing continuous rotation.
What would happen to a DC motor if the commutator were not present?