Basic Electrical Engineering (3110005) MCQs

MCQs of Electrical Machines

Showing 21 to 30 out of 32 Questions
1 2 3 4
21.
By looking at which part of the motor, it can be easily confirmed that a particular motor is DC motor?
(a) Frame
(b) Shaft
(c) Commutator
(d) Stator
Answer:

Option (c)

22.
Which of the following law/rule can be used to determine the direction of rotation of DC motor?
(a) Lenz's law
(b) Faraday's law
(c) Coloumb's law
(d) Fleming's left-hand rule
Answer:

Option (d)

23.
The power mentioned on the nameplate of an electric motor indicates
(a) the power drawn in kW
(b) the power drawn in kVA
(c) the gross power
(d) the output power available at the shaft
Answer:

Option (d)

24.
The speed of a DC motor can be varied by varying
(a) field current
(b) applied voltage
(c) resistance in series with armature
(d) any of the above
Answer:

Option (d)

25.
When the armature of a DC motor rotates, emf induced is
(a) self-induced emf
(b) mutually induced emf
(c) back emf
(d) none of the above
Answer:

Option (c)

26.
Torque developed by a DC motor depends upon
(a) magnetic field
(b) length of the conductors
(c) number of conductors
(d) all of above
Answer:

Option (d)

27.
Synchronous motor always runs at
(a) the synchronous speed
(b) less than synchronous speed
(c) more than synchronous speed
(d) none of above
Answer:

Option (a)

28.
The working of synchronous motor is similar to
(a) gear train arrangement
(b) transmission of mechanical power by shaft
(c) distribution transformer
(d) turbine
Answer:

Option (b)

29.
Mostly, synchronous motors are of
(a) alternator type machines
(b) induction type machines
(c) salient pole type machines
(d) smooth cylinderical type machines
Answer:

Option (c)

30.
In which of the following motors the stator and rotor magnetic field rotate at the same speed?
(a) Universal motor
(b) Synchronous motor
(c) Induction motor
(d) Reluctance motor
Answer:

Option (b)

Showing 21 to 30 out of 32 Questions
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