MCQ’S
1. 1-A 250-V series DC motor with compensating windings, the total series
Resistance is 0.08 ohm. For a field current of 50 A. The armature current is




250
None of them
100
50
2. For Induction motor, in order to reduce starting current__




Inductor
capacitor
autotransformer
None of them
3. In cumulatively compounded generator, the effect of shunt and a series
Fields is




None of them
additive
subtractive
null
4. A pneumatic cylinder produces _______ motion.
 None of them
 non linear
 circular
 linear
5. The armature circuit of a DC machine is found at its ________




Rotor
No armature circuit in DC machines.
Stator
None of them
6. In order to make and or break mechanical contacts between electrical leads
___________ are used.




solenoid
relay
motors
None of them
7. For Synchronous motors, if the maximum possible power of motor is
exceeded, the rotor will not be able to stay locked with _____________.




Internal voltage
None of them
Stator magnetic field
Electrical frequency
8. For a 250-V series DC motor with compensating windings, the total series
resistance is 0.08. For a field current of 50 A. The internally generated voltage
EA is v.
 250
 None of them
 350
 246
9. For Synchronous generator, the internally generated voltage depends upon




phase voltage & armature reaction
None of them
armature resistance & electrical frequency
the rate of shaft rotation & magnitude of field flux
10. A 240 V, shunt DC motor takes an armature current of 20 A when running at
1 point 960 rpm. The armature resistance is 0.2 0. Determine the no load
speed if the no load armature current is 1 A. Internal voltage is
______________ .
 975
 None of them
 800
11.For Synchronous generator, if the unity power factor loads are added to a
generator, then phase and terminal voltages are.




None of them
Decrease
Increase
Remain constant
12.The Amortisseur windings are used to start _____________ machines.
 Synchronous
 Induction
 Induction & Synchronous
 None of them.
13. For an induction motor, the higher the speed of rotation_________ its
core on losses.




0 lower (Correct answer)
0 None of them
0 constant
0 greater
14. The _________ relative motion between the rotor and stator, the
________ would be the rotor voltage and frequency.




15.




lower, lower
greater, greater
greater, lower
none of them
An induction motor can speed up to ____________.
Synchronous Speed
None of them
Asynchronous Speed
Slower Speed
16. The slip and rotor current in three phase induction motor are
________________.
 None of them
 Independent of each other
 Indirectly proportional to each other
 Directly proportional to each other
17.




____________________ Induction motor rotor are rarely used.
cage
wound
None of them
Y- connected
18. In a wound rotor motor, the rotor winding is wound for poles _______
that of 1/1 the stator winding.




equal to
Greater than
Smaller than
None of them
19. If the slip of induction motor increases, then the current in the stator
winding ___________.




20.
None of them
increases
remain constant
decreases
For an induction motor, speed control can be accomplished by
 None of them
 changing the applied terminal voltage
 all except none of them
 changing the number of poles on machine
 changing the applied electrical frequency
21. _______________ Induction motor rotor consists of conducting bars
laid into slots carved in the face of the rotor and shorted at either end by
large shorting rings.
22. For an induction motor the smallest voltage and frequency occurs
when __________.




23.




rotor moves faster than stator magnetic field
rotor moves slower than stator magnetic field
None of them
rotor moves same as stator magnetic field
The Amortisseur windings are used to start___________machines.
Synchronous
Induction
Induction & Synchronous
None of them
24. For Induction motor, the speed at which maximum torque occur can
be controlled by ___________.




Increasing internal voltage
Changing the number of slots
varying the rotor resistance
None of them
25. For Synchronous generator, if the leading power factor loads are added
to a generator, then phase and terminal voltages are ________.




None of them
remain constant
Decrease
increase
26. Three phase motors and generators whose field current is supplied by
magnetic induction in the machine are _________ machines.




Synchronous
None of them
Stepper
Induction
27. A 240 V. shunt DC motor takes an armature current of 20 A when running
at 960 rpm. The armature resistance is 0.2 ohm. Determine the no load
speed if the no load armature current is 1 A. No load speed, when the no
load armature current is 1 A is ___________rpm.




None of them
975
236
800
28. For stable output voltage, the shunt do generator depends on
_________.




Nonlinearity of magnetization curve
None of them
No load voltage
Lines terminal voltage
29. For separately excited DC motors, the speed drops linearly with
________.




Increase in torque
Decrease in torque
Change in field current
None of them
30. For stable output voltage, the shunt do generator depends on
_________.




Nonlinearity of magnetization curve
None of them
No load voltage
Lines terminal voltage
31. For separately excited DC motor, the speed drops linearly with
______________.




Increase in torque
Decrease in torque
Change in field current
None of them
32. In__________ type of DC motors, the rotor will always be an
electromagnet.




None of them
Separately Excited
Self-Excited
Permanent magnet
33. In differentially compounded generator, the effect of shunt and a
series fields no. is ___________.




None of them
null
subtractive
additive
34. For induction motor the higher the speed of rotation ____________ its core
loses.




Higher
Lower
None of them
Constant
35.For Synchronous motors, if the maximum possible power of motor is
exceeded, the rotor will not be able to stay locked with




Stator magnetic field
Internal voltage
Electrical frequency
None of them
36.Three phase motors and generators whose field current is supplied by
magnetic induction in the machine are _________machines.




none of them
Stepper
Synchronous
induction
37.In Cumulatively compounded generator, the effect of shunt and a series
fields is _______________.




subtractive
null
None of them
additive
38. For synchronous generator, if the leading power factor loads are added to a
generator, then phase and terminal voltages are _________________ .




Decrease
None of them
Remain constant
Increase
39.The voltage in any real machine will not depend on factor.
 A constant representing the construction of the machine (the number of
loops, etc.)
 The flux in the machine
 None of them
 Other
40. In order to produce a rotating magneto field only three phase winding are
needed.
 True
 False
41. In a three-posse set 01 currents, each of equal magnitude and differing in
phase by 120°, flows in a three-phase winding, then it will produce a rotating
magnetic field of varying magnitude.
 True
 False
42. In rotating magnetic field, the magnitude of the magnetic field is constant
but ________.




None of them
its direction changes and also remain constant
its direction changes
its direction remain constant O Other: