Explore topic-wise MCQs in Electrical Engineering Questions.

This section includes 102 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.

51.

The voltage control in electric supply networks in required on account of which of the following reasons ?
A. Adjustment of voltage at consumers premises within statutory limits
B. Control of active and reactive power
C. Adjustment of short period daily and seasonal voltage variations in accordance with variations of load
D. All of the above
Answer» E.
Discussion
52.

The forced oil and air circulation method is usual one for transformers of capacities____________?
A. upto 5 MVA
B. upto 10 MVA
C. upto 20 MVA
D. 30 MVA upwards
Answer» E.
Discussion
53.

The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following ?
A. Corrugations
B. Fins
C. Tubes
D. Radiator tanks
E. All of the above
Answer» F.
Discussion
54.

Disc windings are primarily used in_____________-?
A. short capacity transformers
B. medium capacity transformers
C. high capacity transformers
D. any of the above
Answer» D. any of the above
Discussion
55.

D.C. machines designed with a large value of air gap length have_____________?
A. worst, ventilation
B. poor ventilation
C. better ventilation
D. none of the above
Answer» D. none of the above
Discussion
56.

Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ?
A. Increased I R losses
B. Increased core losses
C. Poor commutation
D. Change in motor parameters
E. All of the above
Answer» F.
Discussion
57.

In a D.C. machine the number of brush arms is _________ the number of poles?
A. less than
B. equal to
C. greater than
D. none of the above
Answer» C. greater than
Discussion
58.

The insulation between windings and grounded core and the insulation between the windings of the same phase is called__________________?
A. minor insulation
B. major insulation
C. either of the above
D. none of the above
Answer» C. either of the above
Discussion
59.

In D.C. machines the number of slots per pole usually lies___________?
A. between 2 to 4
B. between 6 to 8
C. between 9 to 16
D. between 20 to 30
Answer» D. between 20 to 30
Discussion
60.

Which of the following methods may be adopted to reduce the effects of armature reaction ?
A. Increase in length of air gap at pole tips
B. Increasing reluctance of pole tips
C. Compensating windings
D. Interpoles
E. All of the above
Answer» F.
Discussion
61.

In D.C. machines, the ________ in field mmf results in increase in size and cost of machines?
A. increase
B. decrease
C. either of the above
D. none of the above
Answer» B. decrease
Discussion
62.

In a D.C. machine the current per brush arm should not be more than_____________?
A. 100 A
B. 200 A
C. 300 A
D. 400 A
Answer» E.
Discussion
63.

The surge phenomenon is particularly important in case of_______________?
A. low voltage transformers
B. medium voltage transformers
C. high voltage transformers
D. any of the above
Answer» D. any of the above
Discussion
64.

____________ is the common method of applying brushes to the commntator?
A. Radial
B. Trailing
C. Reaction
D. All of the above
Answer» E.
Discussion
65.

___________ brushes are fragile and cause excessive wear of commutator?
A. Natural graphite
B. Hard carbon
C. Electro graphitic
D. Metal graphite
Answer» B. Hard carbon
Discussion
66.

D.C. windings are____________?
A. sometimes 2-layer type
B. never 2-layer type
C. always 2-layer type
D. none of the above
Answer» D. none of the above
Discussion
67.

The usual values of maximum flux densities for distribution transformers using hot rolled silicon steel are______________?
A. 0.5 to 0.8 Wb/m2
B. 0.8 to 1.0 Wb/m2
C. 1.1 to 1.35 Wb/m2
D. 1.4 to 1.8 Wb/m2
Answer» D. 1.4 to 1.8 Wb/m2
Discussion
68.

The high voltage winding is usually which of the following type ?
A. Cylindrical winding with circular conductors
B. Cross-over winding with either circular or small rectangular conductors
C. Continuous disc type winding with rectangular conductors
D. All of the above types
Answer» E.
Discussion
69.

The flash point of transformer oil should be higher than_______________?
A. 40°C
B. 60°C
C. 80°C
D. 104°C
Answer» E.
Discussion
70.

The slot leakage can be calculated by making which of the following assumptions ?
A. The current in the slot conductors is uniformly distributed over their cross-section
B. The leakage path is straight across the slot and around the iron at the bottom
C. The permanence of air paths is only considered. The reluctance of iron paths is assumed as zero
D. All of the above
Answer» E.
Discussion
71.

In a D.C. machine, the value of peripheral speed should not, normally, exceed___________?
A. 10 m/s
B. 20 m/s
C. 30 m/s
D. 40 m/s
Answer» D. 40 m/s
Discussion
72.

The operation of a D.C. machine with large air gap lengths is comparatively_____________?
A. quiet
B. noisy
C. either of the above
D. none of the above
Answer» B. noisy
Discussion
73.

In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made____________?
A. equal to that of armature mmf
B. less in comparison with the armature mmf
C. large in comparison with the armature mmf
D. none of the above
Answer» D. none of the above
Discussion
74.

In D.C. machines the usual limit of slot pitch is________________?
A. between 5 to 10 mm
B. between 10 to 15 mm
C. between 15 to 20 mm
D. between 25 to 35 mm
Answer» E.
Discussion
75.

is usually used for brush rockers____________?
A. Mild steel
B. Copper
C. Aluminium
D. Cast-iron
Answer» E.
Discussion
76.

The stator of a D.C. machine comprises of_____________?
A. main poles
B. interpoles
C. frame
D. all of the above
Answer» E.
Discussion
77.

Which of the following in an application of D.C. motors?
A. Traction
B. Drives for process industry
C. Battery driven vehicles
D. Automatic control
E. All of the above
Answer» F.
Discussion
78.

The cylindrical windings using circular conductors are used for current rating of____________?
A. upto 20 A
B. upto 40 A
C. upto 60 A
D. upto 80 A
Answer» E.
Discussion
79.

D.C. servomotors are used in______________?
A. purely D.C. control systems
B. purely AC. control systems
C. both D.C. and AC. control systems
D. none of the above
Answer» B. purely AC. control systems
Discussion
80.

Yokes with rectangular cross-section are used for_______________?
A. small capacity transformers
B. medium capacity transformers
C. large capacity transformers
D. any of the above
Answer» B. medium capacity transformers
Discussion
81.

The laminations of the armature of a D.C. machine are usually ___________ thick?
A. 0.1 to 0.2 mm
B. 0.2 to 0.3 mm
C. 0.3 to 0.4 mm
D. 0.4 to 0.5 mm
Answer» E.
Discussion
82.

The winding where dummy coils are used is sometimes called______________?
A. duplex winding
B. triplex winding
C. forced winding
D. none of the above
Answer» D. none of the above
Discussion
83.

When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of_____________?
A. short pitch
B. full pitch
C. either of the above
D. none of the above
Answer» C. either of the above
Discussion
84.

Power transformers should be designed to have maximum efficiency________________?
A. at one-fourth load
B. at one-half load
C. at or near full load
D. any of the above
Answer» D. any of the above
Discussion
85.

The distance between the starts of two consecutive coils measured in terms of coil sides is called_____________?
A. front pitch
B. winding pitch
C. commutator pitch
D. back pitch
Answer» C. commutator pitch
Discussion
86.

____________are always double layer type?
A. Closed windings
B. Open windings
C. Either of the above
D. None of the above
Answer» B. Open windings
Discussion
87.

Power transformers have rating_______________?
A. equal to 50 kVA
B. equal to 100 kVA
C. above 200 kVA
D. none of the above
Answer» D. none of the above
Discussion
88.

Which of the following methods is used for air cooling of turbo-alternators ?
A. One sided axial ventilation
B. Two sided axial ventilation
C. Multiple inlet system
D. All of the above
Answer» E.
Discussion
89.

In transformers using hot rolled steel, the cross-section of the yoke is made about __________ greater than that of the core?
A. 5 percent
B. 10 percent
C. 15 percent
D. 30 percent
E. none of the above
Answer» D. 30 percent
Discussion
90.

By which of the following methods the temperature rise of windings and other parts may be determined ?
A. Thermometer method
B. Resistance method
C. Embedded temperature detector method
D. Any of the above
Answer» E.
Discussion
91.

The value of exciting or magnetizing current depends upon which of the following factors ?
A. Total m.m.f. required
B. The number of turns in the exciting winding
C. The way in which the winding is distributed
D. All of the above
Answer» E.
Discussion
92.

By which of the following methods motor rating for variable load drives can be determined ?
A. Method of average losses
B. Equivalent current method
C. Equivalent torque method
D. Equivalent power method
E. All of the above
Answer» F.
Discussion
93.

The design of electromagnets is based upon which of the following fundamental equations ?
A. Force equation
B. Magnetic circuit equation
C. Heating equation
D. Voltage equation
E. All of the above
Answer» F.
Discussion
94.

Which of the following is the commonly used type of electromagnets ?
A. Flat-faced armature type
B. Horse shoe type
C. Flat-faced plunger type
D. All of the above
Answer» E.
Discussion
95.

Tractive magnets are operated from____________?
A. a.c. supply
B. d.c. supply
C. either a.c. or d.c. supply
D. none of the above
Answer» E.
Discussion
96.

____________are used for construction of core of electromagnets?
A. Soft magnetic materials
B. Hard magnetic materials
C. Either A. or B.
D. None of the above
Answer» B. Hard magnetic materials
Discussion
97.

Multi-layer helical windings are commonly used in the transformers as high voltage windings_______________?
A. upto 20 kV
B. upto 50 kV
C. upto 80 kV
D. for 110 kV and above
Answer» E.
Discussion
98.

Cylindrical windings using circular conductors, employed in transformers, are_____________?
A. single layered
B. double layered
C. multi-layered
D. none of the above
Answer» D. none of the above
Discussion
99.

The cold rolled grain oriented steel has ___________ permeability in the direction of the grain orientation?
A. minimum
B. maximum
C. nil
D. none of the above
Answer» C. nil
Discussion
100.

Helical windings are used in________________?
A. distribution transformers
B. power transformers
C. shell type transformers
D. none of the above
Answer» C. shell type transformers
Discussion