MULTIPLE CHOICE QUESTIONS
Q.1 Which of the following dc motor has maximum self relieving property:
(A) Shunt
(B) Series
(C) Cumulative compound
(D) Differential compound
Q.2 When the direction of power flow in a differential compounded motor reverses, it will operate as a:
(A) Cumulative compound generator
(B) Differential compound generator
(C) Series motor
(D) Shunt motor
Q.3 A separately excited dc generator is feeding dc shunt motor. If the load torque on the motor is halved approximately, then:
(A) Armature current of both motor and generator are halved
(B) Armature current of motor is halved and that of the generator is unaltered
(C) Armature current of generator is halved and that of the motor is unaltered
(D) Armature current of both motor and generator are unaltered
Q.4 A flywheel is employed with a dc compound motor to reduce the peak demand, the compound motor should be:
(A) Level compound
(B) Differential compound
(C) Cumulative compound
(D) None of the above
Q.5 The flux leakage coefficient in dc machine is usually:
(A) 0.6 to 0.8
(B) 1.05
(C) 1.1 to 1.3
(D) 2 to 2.5
Q.6 Torque development in a dc motor depends on:
(A) Magnetic field and radius of armature
(B) Current flowing through the armature conductors
(C) Active length of the conductors and number of armature conductors
(D) All the above
Q.7 The horse power obtained from the motor shaft is called:
(A) IHP
(B) BHP
(C) Useful torque
(D) None of the above
Q.8 The efficiency of a dc motor when developing maximum power will be about:
(A) 100%
(B) 50%
(C) Less than 50%
(D) More than 50%
Q.9 A dc motor having full load speed of 75 rpm and speed regulation of 10% will have no load speed of:
(A) 825 rpm
(B) 675 rpm
(C) 800 rom
(D) 700 rpm
Q.10 The direction of rotation of a dc compound motor can be reversed by interchanging __ connections:
(A) Armature
(B) Series field
(C) Shunt field
(D) Armature and series field
