This is a sample questions that is provided to test your knowledge which can help you to get jobs like Electrician, Foreman, Supervisor, Assistant Engineer, & Engineer in NEA, NTC, PSC, CANN.
Model question set 9
Multiple Choice Question
1. If the frequency of 3-phase supply to the stator of a 3-phase induction motor is increased then the synchronous speed
is decreased
is increased
remains same
none
2. When a 3-phase induction motor is at no load the slip is
1
0.5
paractically zero
0.2
3. An ideal transformer is one which
has no losses and leakage reactance
does not work
has same no of primary turns and secondary turns
none
4. Hot-wire instruments have ____ scale.
uniform
log
squared
none
5. High-voltage DC machines use ____ winding.
lap
wave
either a or b
none
6. Cumulatively compounded motors are used where we require
variable speed
poor speed regulation
sudden heavy loads for short duration
none
7. A resistance split-phase induction motor is used for
low inertia loads
high inertia loads
very high inertia loads
none
8. When load on an alternator is increased the terminal voltage increases if the load p.f.is
unity
lagging
leading
zero
9. Corona effect
causes power loss in the line
causes interference in radio communication
produces radio frequency waves
all
10. The domestic load that has unity power factor is
fan
mixer
tube
filament lamp
11. Overheating of a transformer may be due to
overloads
short-circuits
failure of cooling system
all
12. A surge diverter should be located _____ the apparatus to be protected.
close to
far away from
in the middle of
none
13. The maximum rectification efficiency of a half wave rectifier is
81.2%
40.6%
50%
25%
14. A transistor is a ____ operated device.
current
voltage
both a & b
none
15. An SCR is a
four layer four junction device
four layer three junction device
four layer two junction device
three layer single junction device
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