Question

Draw a labelled diagram of DC motor.

Answer 1

Hint: A DC motor is a device which converts electrical energy to mechanical energy, the full form of DC motor is, Direct Current Motor, There are a variety of DC motors, like shunt DC, series DC, Permanent magnet DC, etc.

Complete step by step answer:

(i)The diagram is as shown in the figure. An electric motor consists of a rectangular coil of insulated copper wire. The coil is placed between the two poles of a magnetic field in such a way that the arms are perpendicular to the direction of the magnetic field. The ends of the coil are connected to the two halves of a split ring. The inner sides of these halves are insulated and attached to an axle. The external conducting edges of the coil touch two conducting stationary carbon brushes.

(ii)When the coil rotates, the split parts of the ring rotate with it to flow the current in the armature coil in such a way that it always keeps on rotating in the same direction.

(iii)We can store D.C. can store in a battery but A.C. cannot be stored in a battery but AC voltages can be readily transformed lower voltage levels to higher voltage levels and vice versa,and it is quite difficult to carry out voltage ups and downs in DC. This transformation of voltage is required as current has to travel a long way and only high voltage is efficient in that case otherwise there is a loss of current hence AC is preferred over DC .

Note: The carbon brushes given in the DC motor is because when it runs at a very high speed then it sparks can occur damaging the motor hence carbon brushes reduce the sparks caused by electric current.