Question

A motor converts:
A) Mechanical energy into electrical energy
B) Mechanical energy into sound energy
C) Electrical energy into mechanical energy
D) Electrical energy into sound energy

Answer 1

Hint: An electric motor is a rotating device. An electric motor works on the principle that when a current carrying conductor is placed inside two poles of a magnet, it produces a magnetic field around it. This is due to the fact that a force acts on the coil and makes it rotate continuously.

Complete answer:
When the battery is switched on, current starts flowing in the coil. The direction of the magnetic field is from North to South and can be known by Fleming’s Left Hand Rule.
According to this rule, if the thumb, index finger and the middle finger are held mutually perpendicular to each other, then the index finger aligns in the direction of magnetic field, middle finger in the direction of current and the thumb indicates the direction of force on the conductor. It is used to determine the force exerted on a conductor when placed in an external magnetic field.
A motor converts electrical energy into mechanical energy.

Hence, option C is the right answer.

Note: It is important to remember that the electric field and magnetic field exist simultaneously. This means that a changing magnetic field produces an electric field and the changing electric field produces a magnetic field. The machines these days like generators, motors and transformers work on the principle of electromagnetic induction. The law of electromagnetic induction was discovered by Michael Faraday and is known as Faraday’s laws of electromagnetic induction. It was discovered in 1830.