Single phase motor mcq
important single phase motor mcq - electrical Multiple Choice Questions :-
important single phase motor mcq - electrical Multiple Choice Questions :-
1 1. At stand still condition the value
of slip is
(a) Zero
(b) One
(c) Infinity
(d) None of the above
Ans – b
2 2. If the terminal voltage of an
induction motor is decreased then current
(a) Increase
(b) Decrease
(c) Remain same
(d) None
Ans--- b
3 3. As compared to DOL starting method
the star delta starting method must have
(a) High starting current
(b) Low starting current
(c) High torque
(d) Better acceleration
Ans ---- b
4 4. Single phase motors are commercially
manufactured up to
(a) 1 HP
(b) 2 HP
(c) 3 HP
(d) 4 HP
Ans --- b
5 5. Which of the single phase motors
will operate at high power factor –
(a) capacitor start motor
(b) shaded pole motor
(c) capacitor run motor
(d) split phase motor
Ans --- c
6 6. motor used for driving the record
player deck ---
(a) hysteresis motor
(b) dc series motor
(c) synchronous motor
(d) dc shunt motor
Ans ------ a
7 7. a motor speed of 5000 rpm is required,which
motor will you select---
(a) Hysteresis motor
(b) Shaded pole motor
(c) Capacitor start motor
(d) Universal motor
Ans ---- d
8 8. universal motor is operated on no
load, its speed is limited by---
(a) windage and friction
(b) armature weight
(c) armature reaction
(d) supply voltage
Ans ---- a
9 9. which motor following generally
used in ceiling fan ----
(a)
permanent capacitor type
(b)
capacitor start and run
type
(c)
capacitor start type
(d)
split phase type
Ans---- a
1 10.
universal motor operates
on ---
(a)
synchronous speed with varying
load
(b) constant
speed and varying load
(c)
approximately constant
speed and load
(d)
constant load and varying
speed
Ans --- c
1 11.
Which of the
following applications make use of a universal motor ---
(a)
Lathe machines
(b)
Floor polishing machine
(c)
Oil expeller
(d)
Portable
tools
Ans --- d
1 12.
In portable
tools the speed of the driven shaft is reduced by ---
(a)
Fluid coupling
(b)
Gearing
(c)
Chain drive
(d)
Belt drive
Ans – b
1 13.
The capacitance of a
small single phase motor will be of the order of ---
(a)
Micro or
pico farads
(b)
Farads
(c)
Few hundred farads
(d)
Kilo farads
Ans --- a
1 14.
Reluctance
motors are
(a)
singly
excited
(b)
doubly
excited
(c)
both (a) and
(b)
(d)
none of the
above
Ans ---a
1 15.
Which motor is generally
used for electric shavers
(a)
Universal
motor
(b)
Shaded pole
motor
(c)
Hysteresis
motor
(d)
Reluctance
motor
Ans – a
1 16.
motor generally used in
toys is –
(a)
Reluctance motor
(b)
Shaded pole
motor
(c)
Hysteresis
motor
(d)
Two value
capacitor motor
Ans ---b
1 17.
Which of the
following is a reversible motor---
(a)
Capacitor
start split phase motor
(b)
Universal
motor
(c)
Both (A) and
(B)
(d)
None
Ans --- c
1 18.
The starting
torque of a single phase induction motor is ----
(a)
Zero
(b)
Low
(c)
High
(d)
Uniform
Ans --- a
1 19.
The rotor
for a hysteresis motor ---
(a)
is made of
chrome steel
(b) has high hysteresis loss
(c)
has high
retentivity
(d) all of the above
Ans --- d
2 20.
What could
be the smallest size of a universal motor ---
(a)
1/10 HP
(b)
1/20 HP
(c)
1/200 HP
(d)
None of the
above
Ans – c
2 21.
The
disadvantage of shaded pole motor is ----
(a)
very little
over load capacity
(b)
low
efficiency
(c)
low starting
torque
(d)
all of the
above
Ans –d
2 22.
Which of the
following applications would need the smallest size of motor ---
(a)
Table fan
(b)
Electric
clock
(c)
Domestic
motor
(d)
Sewing
machine
Ans --- b
2 23.
When a
dc series motor is connected to ac supply, it will ---
(a)
give poor
efficiency
(b)
run on poor
power factor
(c)
spark
excessively
(d)
all of the
above
Ans --- d
2 24.
In a
shaded pole motor, the direction of rotation is from –
(a)
shaded pole
to main pole
(b)
main pole to
shaded pole
(c)
depends on
supply line polarity
(d)
none of the
above
Ans ----b
25.
In a shaded pole motor,
shading coils are used to—
(a)
reduce
friction losses
(b)
produce
rotating magnetic field
(c)
reduce
windage losses
(d)
to
protect against sparking
Ans ----- b
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