Concept:An electric motor works on the principle that a current-carrying conductor experiences a force when placed inside a magnetic field.
Explanation:The working of an electric motor is based on the interaction between a magnetic field and a current-carrying conductor.
When electric current passes through a conductor placed in a magnetic field, a mechanical force is generated.
This force is called the Lorentz force and it causes the conductor to move.
The direction of this force is found using Fleming's Left-Hand Rule.
According to this rule, the thumb shows the direction of motion, the forefinger shows the direction of the magnetic field, and the middle finger shows the direction of current.
This interaction converts electrical energy into mechanical energy.
The motor keeps rotating because the direction of current is reversed at regular intervals using a commutator.
Therefore, the basic principle of an electric motor is the interaction between a magnetic field and a current-carrying conductor.
Answer:Option A: magnetic field and current-carrying conductors.