DC Motors MCQ - Electrician (Set-1) with Answers

DC Motors MCQ - Electrician (Set-1) with Answers

71) The starting current of a 220V, 10HP shunt motor having an armature resistance of 0.2 ohms, without starter is :

Answer is:

1100 amps

72) A 220V DC machine has an armature resistance of 0.5 ohm. If the armature current is 20 amps, the induced emf when the machine works as (i) generator (ii) motor will be :

Answer is:

230V, 210V

73) A DC shunt motor is running on no-load if the field winding gets opened, what will be the condition of the motor ?

Answer is:

The motor will run at high speed

74) In DC shunt motor, if the field is opened during running, what will happen to the motor ?

Answer is:

The motor runs in dangerous speed and may bum out

75) The D.C shunt motor speed is to be varied from zero to above normal with reversing facility having inherent stability of speed at all loads. What speed control method is to be used ?

Answer is:

Ward-Leonard system of speed control