A. motor is run as a generator
B. motor is reversed in direction
C. motor is run at reduced speed
Related Mcqs:
- If the terminals of armature of D.C. motor are interchanged, this action will offer following kind of braking?
A. regenerative
B. plugging
C. dynamic braking
D. none of the above
E. any of the above - Regenerative method of braking is based on that___________?
A. back e.m.f. is less than the applied voltage
B. back e.m.f. is equal to the applied voltage
C. back e.m.f. of rotor is more than the applied voltage
D. none of the above - For which types of D.C. motor, dynamic braking is generally used ?
A. Shunt motors
B. Series motors
C. Compound motors
D. All of the above - Which method of braking is generally used in elevators ?
A. Plugging
B. Regenerative braking
C. Rheostatic braking
D. None of the above - The direction of rotation of a D.C. series motor can be changed by___________?
A. interchanging supply terminals
B. interchanging field terminals
C. either of A. and B. above
D. None of the above - A D.C. series motor is that which______________?
A. has its field winding consisting of thick wire and less turns
B. has a poor torque
C. can be started easily without load
D. has almost constant speed - The speed of a D.C. series motor is_____________?
A. proportional to the armature current
B. proportional to the square of the armature current
C. proportional to field current
D. inversely proportional to the armature current - D.C. series motors are used______________?
A. where load is constant
B. where load changes frequently
C. where constant operating speed is needed
D. in none of the above situations - Which of the following tests will be suitable for testing two similar D.C. series motors of large capacity ?
A. Swinburne’s test
B. Hopkinson’s test
C. Field test
D. Brake test - A dc series motor should not be started on no load because it would___________?
A. not develop starting torque
B. fail to start without load
C. run at dangerously high speed
D. draw more current without producing sufficient torque
