DC MOTOR MCQS SET 11

DC MOTOR MCQS SET 11

1. If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens
(a) this will make armature to take heavy current, possibly burning it
(6) this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses
(c) nothing will happen to motor
(d) motor will come to stop
Ans:  a

2. D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value for short duration. We will select the
(a) series motor
(b) shunt motor
(c) compound motor
(d) any of the above 
Ans:  a
3. D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select this
(a) series motor
(b) shunt motor
(c) compound motor
(d) any of the above
Ans:  c
4. Which D.C. motor has got maximum self relieving property ?
(a) Series motor
(6) Shunt motor
(c) Cumulatively compounded motor
(d) Differentially compounded motor 
Ans:  a
5. In the D.C. motor the iron losses occur in
(a) the field
(b) the armature
(c) the brushes
(d) the commutator
Ans:  b

6. The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by
(a) reducing the field current
(b) decreasing the armature current
(c) increasing the armature current
(d) increasing the excitation current
(e) none of the above methods 
Ans:  a
7. One D.C. motor drives another D.C. motor. The second D.C. motor when excited and
driven
(a) runs as a generator
(b) does not run as a generator
(c) also runs as a motor comes to stop after sometime
Ans:  a