MCQs | Single Phase Motors | Electrical Machine Questions
MCQ types Questions and Answers of single phase motor are provided below which is more important to grow knowledge about electrical machine Questions and for GATE examination also.
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| MCQs | Single Phase Motors | Electrical Machine Questions |
Questions and Answers ( single phase motors)
Q.1
Which of the following single phase motors has relatively poor starting torque?
(a) universal Motor
(b) repulsion Motor
(c) capacitor Motor
(d) all single phase motors have zero starting torque
Ans.
(c) capacitor Motor
Q.2
Which type of load is offered by cranes and hoist?
(a) Gradually varying load
(b) Non reversing, No load start
(c) Reversing, light start
(d) Reversing, Heavy start
Ans.
(d) Reversing, Heavy start
Q.3
The speed of a universal motor is
generally reduced by using
(a)gear trains
(b)V-belts
(c)brakes
(d)chains
Ans.
(a)gear trains
Q.4
Which of the following motors can be
used for unity power factor?
(a)Capacitor run motor
(b)Shaded pole motor
(c)Hysteresis motor
(d) Schrage motor
Ans.
(d) Schrage motor
Q.5
When a D.C. series motor is connected
to A.C. supply, the power factor will be
low because of
(a)high inductance .of field and ar-
mature circuits
(b)induced current in rotor due to
variations of flux
(c)fine copper wire winding
(d)none of the above
Ans.
(a)high inductance .of field and ar-
mature circuits
Q.6.
The direction of rotation of universal
motor can be reversed the by reversing
the flow of current through
(a)armature winding
(b)field winding
(c) either armature winding or field
winding
(d)none of the above
Ans.
(c) either armature winding or field
winding
Q.7
In which single-phase motor, the rotor
has no teeth or winding?
(a)Split phase motor
(b)Reluctance motor
(c)Hysteresis motor
(d)Universal motor
Ans.
(c)Hysteresis motor
Q.8
Which motor is normally free from
mechanical and magnetic vibrations?
(a)Split phase motor
(b)Universal motor
(c)Hysteresis motor
(d)Shaded pole motor
Ans.
(c)Hysteresis motor
Q.9
As hysteresis motors are free from
mechanical and magnetic vibrations
therefore these are considered as
suitable for
(a)fans
(b)blowers
(c)sound equipment
(d)mixer grinders
Ans.
(c)sound equipment
Q.10
A reluctance motor
(a)is self-starting
(b)is constant speed motor
(c)needs no D.C. excitation
(d) all of the above
Ans.
(d) all of the above
Q.11
In a hysteresis motor, the rotor must
have
(a)retentively
(b)resistivity
(c)susceptibility
(d)none of the above
Ans.
(c)susceptibility
Q.12
The rotor of a hysteresis motor is made
of
(a)aluminum
(b)cast iron
(c)chrome steel
(d)copper
Ans.
(c)chrome steel
Q.13
The electric motor used in portable
drills is
(a)capacitor run motor
(b)hysteresis motor
(c)universal motor
(d)repulsion motor
Ans.
(c)universal motor
Q.14
Which of the following applications
always have some load whenever
switched on?
(a)Vacuum cleaners
(6)Fan motors
(c)Pistol drills
(d)All of the above
Ans.
(c)Pistol drills
Q.15
The speed control of universal motor
used for sewing machines is by
(a)friction.
(b)varying the resistance
(c)tapping the field
(d)centrifugal mechanism
Ans.
(b)varying the resistance
