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Free download in PDF Electrical Measuring Instruments Objective Type Questions & Answers for competitive exams. These objective type questions are very important for competitive exams of Engineering. These short solved questions or quizzes are provided by Gkseries.
(21)
Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?
[A]
Absolute instruments
[B]
Indicating instruments
[C]
Recording instruments
[D]
Integrating instruments
Answer: Indicating instruments
(22)
A moving-coil permanent-magnet instrument can be used as flux-meter
[A]
by using a low resistance shunt
[B]
by using a high series resistance
[C]
by eliminating the control springs
[D]
by making control springs of large moment of inertia
Answer: by eliminating the control springs
(23)
An induction meter can handle current up to
[A]
10 A
[B]
30 A
[C]
60 A
[D]
100 A
(24)
Which of the following meters are not used on D.C. circuits
[A]
Mercury motor meters
[B]
Commutator motor meters
[C]
Induction meters
[D]
None of the above
(25)
The pointer of an indicating instrument should be
[A]
very light
[B]
very heavy
[C]
either (a) or (b)
[D]
neither (a) nor (b)
(26)
An ammeter is a
[A]
secondary instrument
[B]
absolute instrument
[C]
recording instrument
[D]
integrating instrument
Answer: secondary instrument
(27)
A moving iron instrument can be used for
[A]
D.C. only
[B]
A.C. only
[C]
both D.C. and A.C.
[D]
None of these
Answer: both D.C. and A.C.
(28)
In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The
power factor of the load must be
[A]
unity
[B]
0.5
[C]
0.3
[D]
zero
(29)
For measuring a very high resistance we should use
[A]
Kelvin's double bridge
[B]
Wheat stone bridge
[C]
Meggar
[D]
None of the above
(30)
The operating voltage of a meggar is about
[A]
6 V
[B]
12 V
[C]
40 V
[D]
100 V
31
It is required to measure the true open circuit e.m.f. of a battery. The best device is
[A]
D.C. voltmeter
[B]
Ammeter and a known resistance
[C]
D.C. potentiometer
[D]
None of the above
Answer: D.C. potentiometer
32
In an AC. co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be
[A]
out of phase by 90°
[B]
out of phase by 60°
[C]
out of phase by 30°
[D]
out of phase by 0°
Answer: out of phase by 90°
33
In an Anderson bridge, the unknown inductance is measured in terms of
[A]
known inductance and resistance
[B]
known capacitance and resistance
[C]
known resistance
[D]
known inductance
Answer: known capacitance and resistance
34
For measurement of mutual inductance we can use
[A]
Anderson bridge
[B]
Maxwell's bridge
[C]
Heaviside bridge
[D]
Any of the above
35
If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is
[A]
10°
[B]
80°
[C]
120°
[D]
170°
36
In a Schering bridge the potential of the detector above earth potential is
[A]
a few volts only
[B]
1 kV
[C]
5 kV
[D]
10 kV
37
A power factor meter has
[A]
one current circuit and two pressure circuits
[B]
one current circuit and one pressure circuit
[C]
two current circuits and one pres¬sure circuit
[D]
none of the above
Answer: one current circuit and two pressure circuits
38
In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at
[A]
0°
[B]
60°
[C]
90°
[D]
120°
39
In a Weston frequency meter, the magnetic axes of the two fixed coils are
[A]
parallel
[B]
perpendicular
[C]
inclined at 60°
[D]
inclined at 120°
40
The power factor of a single phase load can be calculated if the instruments available are
[A]
one voltmeter and one ammeter
[B]
one voltmeter, one ammeter and one wattmeter
[C]
one voltmeter, one ammeter and one energy meter
[D]
any of the above
Answer: one voltmeter, one ammeter and one wattmeter
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