Question

Observe the following diagram and answer the questions.

(a) Construction of which equipment does the following diagram show?

(b) On which principle does this equipment work?

(c) According to which law does the coil ABCD rotate?

(d) Write the law in your own words.

(e) Where is this equipment used?

Answer 1

(a) Given diagram shows the construction of an electric motor.

(b) An electric motor works on the principle that a current-carrying conductor placed in a magnetic field experiences a force. In this case, the forces acting on different parts of the coil of the motor produce the rotational motion of the coil.

(c) The rotation of the coil is based on Fleming’s left hand rule.

(d) Fleming’s left hand rule: The left hand thumb, index finger, and the middle finger are stretched so as to be perpendicular to each other. If the index finger is in the direction of the magnetic field, and the middle finger points in the direction of the current, then the direction of the thumb in the direction of the force on the conductor.

(e) Uses / applications of an electric motor: 

(1) In domestic appliances such as a mixer, a blender, a refrigerator and washing machine. 

(2) In an electric fan, a hair dryer, a record player, a tape recorder and a blower. 

(3) In an electric car, a rolling mill, an electric crane, an electric lift, a pump, a computer and an electric train.