Explore topic-wise MCQs in Electrical Engineering.

This section includes 165 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

An induction motor is

A. elf-starting with zero torque
B. elf-starting with high torque
C. elf-starting with low torque
D. on-self starting
Answer» D. on-self starting
Discussion
52.

In case of the induction motors the torque is

A. nversely proportional to (V-slip)
B. irectly proportional to (slip)2
C. nversely proportional to slip
D. irectly proportional to slip
Answer» E.
Discussion
53.

Temperature of the stator winding of a three phase induction motor is obtained by

A. esistance rise method
B. hermometer method
C. mbedded temperature method
D. ll above methods
Answer» E.
Discussion
54.

For driving high inertia loads best type of induction motor suggested is

A. lip ring type
B. quirrel-cage type
C. ny of the above
D. one of the above
Answer» B. quirrel-cage type
Discussion
55.

In case the air gap in an induction motor is increased

A. he magnetizing current of the rotor will decrease
B. he power factor will decrease
C. peed of motor will increase
D. he windage losses will increase
Answer» C. peed of motor will increase
Discussion
56.

For which motor the speed can be controlled from rotor side?

A. quirrel-cage induction motor
B. lip-ring induction motor
C. oth (A) and (B)
D. one of the above
Answer» C. oth (A) and (B)
Discussion
57.

Lubricant used for ball bearing is usually

A. raphite
B. rease
C. ineral oil
D. olasses
Answer» C. ineral oil
Discussion
58.

If a 3-phase supply is given to the stator and rotor is short circuited rotor will move

A. n the opposite direction as the direction of the rotating field
B. n the same direction as the direction of the field
C. n any direction depending upon phase sequence of supply
D. one of these
Answer» C. n any direction depending upon phase sequence of supply
Discussion
59.

The stating torque of the slip ring induction motor can be increased by adding

A. xternal inductance to the rotor
B. xternal resistance to the rotor
C. xternal capacitance to the rotor
D. oth resistance and inductance to rotor
Answer» C. xternal capacitance to the rotor
Discussion
60.

Rotor rheostat control method of speed control is used for

A. quirrel-cage induction motors only
B. lip ring induction motors only
C. oth (A) and (B)
D. one of the above
Answer» C. oth (A) and (B)
Discussion
61.

The starting torque of a three phase induction motor can be increased by

A. ncreasing slip
B. ncreasing current
C. oth (A) and (B)
D. one of the above
Answer» D. one of the above
Discussion
62.

The efficiency of an induction motor can be expected to be nearly~!

A. 60 to 90 %
B. 80 to 90 %
C. 95 to 98 %
D. 99 %
Answer» C. 95 to 98 %
Discussion
63.

The torque developed in the cage induction motor with auto-starter is~!

A. k/torque with direct switching
B. K √ó torque with direct switching
C. K2 √ó torque with direct switching
D. k2/torque with direct switching
Answer» D. k2/torque with direct switching
Discussion
64.

The stating torque of the slip ring induction motor can be increased by adding%!

A. External inductance to the rotor
B. External resistance to the rotor
C. External capacitance to the rotor
D. Both resistance and inductance to rotor
Answer» C. External capacitance to the rotor
Discussion
65.

The frame of an induction motor is usually made of%!

A. Silicon steel
B. Cast iron
C. Aluminium
D. Bronze
Answer» C. Aluminium
Discussion
66.

A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor%!

A. Will continue running burning its one phase
B. Will continue running burning its two phases
C. Will stop and carry heavy current causing permanent damage to its winding
D. Will continue running without any harm to the winding
Answer» B. Will continue running burning its two phases
Discussion
67.

Low voltage at motor terminals is due to%!

A. Inadequate motor wiring
B. Poorly regulated power supply
C. Any one of the above
D. None of the above
Answer» D. None of the above
Discussion
68.

In an induction motor if air-gap is increased%!

A. The power factor will be low
B. Windage losses will be more
C. Bearing friction will reduce
D. Copper loss will reduce in an induction motor
Answer» B. Windage losses will be more
Discussion
69.

What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero?%!

A. The slip of the motor will be 5%
B. The rotor will not run
C. The rotor will run at very high speed
D. The torque produced will be very large
Answer» C. The rotor will run at very high speed
Discussion
70.

When the equivalent circuit diagram of double squirrel-cage induction motor is constructed the two cages can be considered%!

A. In series
B. In parallel
C. In series-parallel
D. In parallel with stator
Answer» C. In series-parallel
Discussion
71.

In squirrel cage induction motors, the rotor slots are usually given slight skew in order to%!

A. Reduce windage losses
B. Reduce eddy currents
C. Reduce accumulation of dirt and dust
D. Reduce magnetic hum
Answer» E.
Discussion
72.

In an induction motor, no-load the slip is generally%!

A. Less than 1 %
B. 1.5 %
C. 2 %
D. 4 %
Answer» B. 1.5 %
Discussion
73.

The number of slip rings on a squirrel cage induction motor is usually%!

A. Two
B. Three
C. Four
D. None
Answer» E.
Discussion
74.

*$_The frame of an induction motor is usually made of?

A. Silicon steel
B. Cast iron
C. Aluminium
D. Bronze
Answer» C. Aluminium
Discussion
75.

*/*_The stating torque of the slip ring induction motor can be increased by adding?

A. External inductance to the rotor
B. External resistance to the rotor
C. External capacitance to the rotor
D. Both resistance and inductance to rotor
Answer» C. External capacitance to the rotor
Discussion
76.

*/*_An induction motor is identical to?

A. D.C. compound motor
B. D.C. series motor
C. Synchronous motor
D. Asynchronous motor
Answer» E.
Discussion
77.

*/*_Insertion of resistance in the rotor of an induction motor to develop a given torque?

A. Decreases the rotor current
B. Increases the rotor current
C. Rotor current becomes zero
D. Rotor current remains same
Answer» E.
Discussion
78.

*/*_The torque developed by a 3-phase induction motor least depends on?

A. Rotor current
B. Rotor power factor
C. Rotor e.m.f.
D. Shaft diameter
Answer» E.
Discussion
79.

*/*_The speed of a squirrel-cage induction motor can be controlled by all of the following except?

A. Changing supply frequency
B. Changing number of poles
C. Changing winding resistance
D. Reducing supply voltage
Answer» D. Reducing supply voltage
Discussion
80.

*/*_Low voltage at motor terminals is due to?

A. Inadequate motor wiring
B. Poorly regulated power supply
C. Any one of the above
D. None of the above
Answer» D. None of the above
Discussion
81.

*/*_The 'cogging' of an induction motor can be avoided by?

A. Proper ventilation
B. Using DOL starter
C. Autotransformer starter
D. Having number of rotor slots more or less than the number of stator slots (not equal)
Answer» E.
Discussion
82.

*/*_For driving high inertia loads best type of induction motor suggested is?

A. Slip ring type
B. Squirrel-cage type
C. Any of the above
D. None of the above
Answer» B. Squirrel-cage type
Discussion
83.

*/*_An induction motor is?

A. Self-starting with zero torque
B. Self-starting with high torque
C. Self-starting with low torque
D. Non-self starting
Answer» D. Non-self starting
Discussion
84.

*/*_For which motor the speed can be controlled from rotor side??

A. Squirrel-cage induction motor
B. Slip-ring induction motor
C. Both (A) and (B)
D. None of the above
Answer» C. Both (A) and (B)
Discussion
85.

*/*_A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor?

A. Will continue running burning its one phase
B. Will continue running burning its two phases
C. Will stop and carry heavy current causing permanent damage to its winding
D. Will continue running without any harm to the winding
Answer» B. Will continue running burning its two phases
Discussion
86.

*/*_In squirrel cage induction motors, the rotor slots are usually given slight skew in order to?

A. Reduce windage losses
B. Reduce eddy currents
C. Reduce accumulation of dirt and dust
D. Reduce magnetic hum
Answer» E.
Discussion
87.

*/*_When the equivalent circuit diagram of double squirrel-cage induction motor is constructed the two cages can be considered?

A. In series
B. In parallel
C. In series-parallel
D. In parallel with stator
Answer» C. In series-parallel
Discussion
88.

*/*_What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero??

A. The slip of the motor will be 5%
B. The rotor will not run
C. The rotor will run at very high speed
D. The torque produced will be very large
Answer» C. The rotor will run at very high speed
Discussion
89.

*/*_In an induction motor if air-gap is increased?

A. The power factor will be low
B. Windage losses will be more
C. Bearing friction will reduce
D. Copper loss will reduce in an induction motor
Answer» B. Windage losses will be more
Discussion
90.

*/*_The number of slip rings on a squirrel cage induction motor is usually?

A. Two
B. Three
C. Four
D. None
Answer» E.
Discussion
91.

*/*_In an induction motor, no-load the slip is generally?

A. Less than 1 %
B. 1.5 %
C. 2 %
D. 4 %
Answer» B. 1.5 %
Discussion
92.

*/*_Rotor rheostat control method of speed control is used for?

A. Squirrel-cage induction motors only
B. Slip ring induction motors only
C. Both (A) and (B)
D. None of the above
Answer» C. Both (A) and (B)
Discussion
93.

*/*_As load on an induction motor goes on increasing?

A. Its power factor goes on decreasing
B. Its power factor remains constant
C. Its power factor goes on increasing even after full load
D. Its power factor goes on increasing up to full load and then it falls again
Answer» E.
Discussion
94.

%_As load on an induction motor goes on increasing_%

A. Its power factor goes on decreasing
B. Its power factor remains constant
C. Its power factor goes on increasing even after full load
D. Its power factor goes on increasing up to full load and then it falls again
Answer» E.
Discussion
95.

_ Rotor rheostat control method of speed control is used for$?

A. Squirrel-cage induction motors only
B. Slip ring induction motors only
C. Both (A) and (B)
D. None of the above
Answer» C. Both (A) and (B)
Discussion
96.

_ The vafcie of transformation ratio of an induction motor can be found by$?

A. Open-circuit test only
B. Short-circuit test only
C. Stator resistance test
D. None of the above
Answer» C. Stator resistance test
Discussion
97.

_ Which of the following component is usually fabricated out of silicon steel?$?

A. Bearings
B. Shaft
C. Stator core
D. None of the above
Answer» D. None of the above
Discussion
98.

_ Slip of an induction motor is negative when$?

A. Magnetic field and rotor rotate in opposite direction
B. Rotor speed is less than the synchronous speed of the field and are in the same direction
C. Rotor speed is more than the synchronous speed of the field and are in the same direction
D. None of the above
Answer» D. None of the above
Discussion
99.

_ Reduced voltage starter can be used with$?

A. Slip ring motor only but not with squirrel cage induction motor
B. Squirrel cage induction motor only but not with slip ring motor
C. Squirrel cage as well as slip ring induction motor
D. None of the above
Answer» D. None of the above
Discussion
100.

_ A 3-phase slip ring motor has$?

A. Double cage rotor
B. Wound rotor
C. Short-circuited rotor
D. Any of the above
Answer» C. Short-circuited rotor
Discussion