Latest Measurement & Instrumentation Objective Questions For Freshers
1.The chemical effect of current is used in
D.C. ammeter hour meter
D.C. ammeter
D.C. energy meter
none of the above
ANSWER : : D.C. ammeter hour meter
2.Which of the following meters are not used on D.C. circuits
Mercury motor meters
Commutator motor meters
Induction meters
None of the above
ANSWER : : Induction meters
3.Which of the following essential features is possessed by an indicating instrument ?
Deflecting device
Controlling device
Damping device
All of the above
ANSWER : : All of the above
4.In a portable instrument, the controlling torque is provided by
spring
gravity
eddy currents
all of the above
ANSWER : : spring
5._____ instruments are those which measure the total quantity of electricity delivered in a particular time.
Absolute
Indicating
Recording
Integrating
ANSWER : : Integrating
6.Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?
Absolute instruments
Indicating instruments
Recording instruments
Integrating instruments
ANSWER : : Indicating instruments
7.In majority of instruments damping is provided by
fluid friction
spring
eddy currents
all of the above
ANSWER : : eddy currents
8.For handling greater currents induction wattmeters are used in conjunction with
potential transformers
current transformers
power transformers
either of the above
ANSWER : : current transformers
9.A moving-coil permanent-magnet instrument can be used as _____ by using a low resistance shunt.
ammeter
voltmeter
flux-meter
ballistic galvanometer
ANSWER : : ammeter
10.The disc of an instrument using eddy current damping should be of
conducting and magnetic material
non-conducting and magnetic material
conducting and non-magnetic material
none of the above
ANSWER : : conducting and non-magnetic material
11.The pointer of an indicating instrument should be
very light
very heavy
either (a) or (b)
neither (a) nor (b)
ANSWER : : very light
12.Most common form of A.C. meters met with in every day domestic and industrial installations are
mercury motor meters
commutator motor meters
induction type single phase energy meters
all of the above
ANSWER : : induction type single phase energy meters
13.Which of the following are integrating instruments ?
Ammeters
Voltmeters
Wattmeters
Ampere-hour and watt-hour meters
ANSWER : : Ampere-hour and watt-hour meters
14.Which of the following is an essential part of a motor meter ?
An operating torque system
A braking device
Revolution registering device
All of the above
ANSWER : : All of the above
15.A moving-coil permanent-magnet instrument can be used as flux-meter
by using a low resistance shunt
by using a high series resistance
by eliminating the control springs
by making control springs of large moment of inertia
ANSWER : : by eliminating the control springs
16.Induction type single phase energy meters measure electric energy in
kW
Wh
kWh
VAR
ANSWER : : kWh
17.An induction meter can handle current upto
10 A
30 A
60 A
100 A
ANSWER : : 100 A
18.A potentiometer may be used for
measurement of resistance
measurement of current
calibration of ammeter & calibration of voltmeter
all of the above
ANSWER : : all of the above
19.The household energy meter is
an indicating instrument
a recording instrument
an integrating instrument
none of the above
ANSWER : : an integrating instrument
20.Resistances can be measured with the help of
wattmeters
voltmeters
ammeters
ohmmeters and resistance bridges
ANSWER : : ohmmeters and resistance bridges
21.A _____ device prevents the oscillation of the moving system and enables the latter to reach its final position quickly
deflecting
controlling
damping
any of the above
ANSWER : : damping
22.is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another,
Tangent galvanometer
Meggar
Current transformer
None of the above
ANSWER : : Meggar
23.An ammeter is a
secondary instrument
absolute instrument
recording instrument
integrating instrument
ANSWER : : secondary instrument
24.In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was
unity
0.8 lagging
0.8 leading
zero
ANSWER : : unity
25.A moving iron instrument can be used for
D.C. only
A.C. only
both D.C. and A.C.
both D.C. and A.C.
ANSWER : The scale of a rectifier instrument is
26.When a capacitor was connected to the terminal of ohmmeter, the pointer indicated a low resistance initially and then slowly came to infinity position. This shows that capacitor is
short-circuited
all right
faulty
all right
ANSWER : For measuring a very high resistance we should use
27.A dynamometer wattmeter can be used for
both D.C. and A.C.
D.C. only
A.C. only
any of the above
ANSWER : : both D.C. and A.C.
28.An ohmmeter is a
moving iron instrument
moving coil instrument
dynamometer instrument
none of the above
ANSWER : : moving coil instrument
29.In a low power factor wattmeter the pressure coil is connected
to the supply side of the current coil
to the load side of the current coil
in any of the two meters at connection
none of the above
ANSWER : : to the load side of the current coil
30.Murray loop test can be used for location of
ground fault on a cable
short circuit fault on a cable
both the ground fault and the short-circuit fault
none of the above
ANSWER : : both the ground fault and the short-circuit fault
31.An induction wattmeter can be used for
both D.C. and A.C.
D.C. only
A.C. only
any of the above
ANSWER : : D.C. only
32.It is required to measure the true open circuit e.m.f. of a battery. The best device is
D.C. voltmeter
Ammeter and a known resistance
D.C. potentiometer
None of the above
ANSWER : : D.C. potentiometer
33.The operating voltage of a meggar is about
6 V
12 V
40 V
100 V
ANSWER : : 100 V
34.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
unity
0.5
0.3
zero
ANSWER : : 0.5
35.In a low power factor wattmeter the compensating coil is connected
in series with current coil
in parallel with current coil
in series with pressure coil
in parallel with pressure coil
ANSWER : : in series with pressure coil
36.For measuring current at high frequency we should use
moving iron instrument
electrostatic instrument
thermocouple instrument
none of the above
ANSWER : : thermocouple instrument
37.Which of the following devices should be used for accurate measurement of low D.C. voltage ?
Small range moving coil voltmeter
D.C. potentiometer
Small range thermocouple voltmeter
None of the above
ANSWER : : D.C. potentiometer
38.The adjustment of position of shading bands, in an energy meter is done to provide
friction compensation
creep compensation
braking torque
none of the above
ANSWER : : friction compensation
39.The electrical power to a meggar is provided by
battery
permanent magnet D.C. generator
AC. generator
any of the above
ANSWER : : permanent magnet D.C. generator
40.A voltage of about 200 V can be measured
directly by a D.C. potentiometer
a D.C. potentiometer in conjunction with a volt ratio box
a D.C. potentiometer in conjunction with a known resistance
none of the above
ANSWER : : a D.C. potentiometer in conjunction with a volt ratio box
41.The function of shunt in an ammeter is to
by pass the current
increase the sensitivity of the ammeter
increase the resistance of ammeter
none of the above
ANSWER : : by pass the current
42.The resistance in the circuit of the moving coil of a dynamometer wattmeter should be
almost zero
low
high
none of the above
ANSWER : : high
43.The multiplier and the meter coil in a voltmeter are in
series
parallel
series-parallel
none of the above
ANSWER : : series
44.In a meggar controlling torque is provided by
spring
gravity
coil
eddy current
ANSWER : : coil
45.The pressure coil of a wattmeter should be connected on the supply side of the current coil when
load impedance is high
load impedance is low
supply voltage is low
none of the above
ANSWER : : load impedance is high
46.In a single phase power factor meter the phase difference between the currents in the two pressure coils is
exactly 0�
approximately 0�
exactly 90�
approximately 90�
ANSWER : : exactly 90�
47.For measurements on high voltage capacitors, the suitable bridge is
Wein bridge
Modified De Santy’s bridge
Schering bridge
Any of the above
ANSWER : : Schering bridge
48.If an inductance is connected in one arm of bridge and resistances in the remaining three arms
the bridge can always be balanced
the bridge cannot be balanced
the bridge can be balanced if the resistances have some specific values
the bridge cannot be balanced
ANSWER : A power factor meter has
49.To measure a resistance with the help of a potentiometer it is
necessary to standardise the potentiometer
not necessary to standardise the potentiometer
necessary to use a volt ratio box in conjunction with the potentiometer
none of the above
ANSWER : : not necessary to standardise the potentiometer
50.A universal RLC bridge uses
Maxwell bridge configuration for measurement of inductance and De Santas bridge for measurement of capacitance
Maxwell Wein bridge for measurement of inductance and modified De Santy’s bridge for measurement of capacitance
Maxwell Wein bridge for measurement of inductance and Wein bridge for measurement of capacitance
Any of the above.
ANSWER : : Maxwell Wein bridge for measurement of inductance and modified De Santy’s bridge for measurement of capacitance
51.To avoid the effect of stray magnetic field in A.C. bridges we can use
magnetic screening
Wagner earthing device
wave filters
any of the above
ANSWER : s: a
52.To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken
from a source which is not the same as the unknown voltage
from a battery
from the same source as the unknown voltage
any of the above
ANSWER : : from the same source as the unknown voltage
53.In an AC. co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be
out of phase by 90�
out of phase by 60�
out of phase by 30�
out of phase by 0�
ANSWER : : out of phase by 90�
54.In order to achieve high accuracy, the slide wire of a potentiometer should be
as long as possible
as short as possible
neither too small not too large
very thick
ANSWER : : as long as possible
55.In a vibrating reed frequency meter the natural frequencies of two adjacent reeds have a difference of
0.1 Hz
0.25 Hz
0.5 Hz
1.5 Hz
ANSWER : : 0.5 Hz
56.A Weston synchronoscope is a
moving coil instrument
moving iron instrument
dynamometer instrument
none of the above
ANSWER : : dynamometer instrument
57.In Weston synchronoscope the moving coil is connected across
bus-bars
incoming alternator
fixed coils
any of the above
ANSWER : : bus-bars
58.A Weston frequency meter is
moving coil instrument
moving iron instrument
dynamometer instrument
none of the above
ANSWER : s: b
59.For measurement of mutual inductance we can use
Anderson bridge
Maxwell’s bridge
Heaviside bridge
Any of the above
ANSWER : : Heaviside bridge
60.A phase shifting transformer is used in conjunction with
D.C. potentiometer
Drysdale potentiometer
A.C. co-ordinate potentiometer
Crompton potentiometer
ANSWER : s: b
61.In a Weston synchronoscope, the fixed coils are connected across
bus-bars
incoming alternator
a lamp
none of the above
ANSWER : : incoming alternator
62.Wagner earthing device is used to eliminate errors due to
electrostatic coupling
electromagnetic coupling
both (a) and (b)
none of the above
ANSWER : : electrostatic coupling
63.Basically a potentiometer is a device for
comparing two voltages
measuring a current
comparing two currents
measuring a voltage
ANSWER : : comparing two voltages
64.In a Weston frequency meter, the magnetic axes of the two fixed coils are
parallel
perpendicular
inclined at 60�
inclined at 120�
ANSWER : : perpendicular
65.In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at
0�
60�
90�
120�
ANSWER : : 120�
66.In a Schering bridge the potential of the detector above earth potential is
a few volts only
1 kV
5 kV
10 kV
ANSWER : : a few volts only
67.The two pressure coils of a single phase power factor meter have
the same dimensions and the same number of turns
the same dimension but different number of turns
the same number of turns but different dimensions
none of the above
ANSWER : : the same dimensions and the same number of turns
68.The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a
single-phase winding
two-phase winding
three-phase winding
any of the above
ANSWER : : two-phase winding
69.If the current in a capacitor leads the voltage by 80�, the loss angle of the capacitor is
10�
80�
120�
170�
ANSWER : : 10�
70.In an Anderson bridge, the unknown inductance is measured in terms of
known inductance and resistance
known capacitance and resistance
known resistance
known inductance
ANSWER : : known capacitance and resistance
71.The ratio of maximum displacement deviation to full scale deviation of the instrument is called
static sensitivity
dynamic deviation
linearity
precision or accuracy
ANSWER : : linearity
72.The rectifier instrument is not free from
temperature error
wave shape error
frequency error
all of the above
ANSWER : : frequency error
73.Wattmeter cannot be designed on the principle of
electrostatic instrument
thermocouple instrument
moving iron instrument
electrodynamic instrument
ANSWER : : moving iron instrument
74.Volt box is a component to
extend voltage range
measure voltage
compare voltage in a box
none of the above
ANSWER : : extend voltage range
75.Commonly used instruments in power system measurement are
induction
moving coil or iron
rectifier
electrostatic
ANSWER : : induction
76.Two holes in the disc of energymeter are drilled at the opposite sides of the spindle to
improve its ventilation
eliminate creeping at no load
increase its deflecting torque
increase its braking tcrque
ANSWER : : eliminate creeping at no load
77.Operating torques in analogue instruments are
deflecting and control
deflecting and damping
deflecting, control and damping
vibration and balancing
ANSWER : : deflecting, control and damping
78.Instrument transformers are
potential transformers
current transformers
both (a) and (b)
power transformers
ANSWER : : both (a) and (b)
79.Damping of the Ballistic galvanometer is made small to
get first deflection large
make the system oscillatory
make the system critically damped
get minimum overshoot
ANSWER : : get first deflection large
80.The desirable static characteristics of a measuring system are
accuracy and reproducibility
accuracy, sensitivity and reproducibility
drift and dead zone
static error
ANSWER : : accuracy, sensitivity and reproducibility
81.Systematic errors are
instrumental errors
environmental errors
observational errors
all of the above
ANSWER : : all of the above
82.In an energymeter braking torque is produced to
safe guard it against creep
brake the instrument
bring energy meter to stand still
maintain steady speed and equal to driving torque
ANSWER : : maintain steady speed and equal to driving torque
83.An instrument transformer is used to extend the range of
induction instrument
electrostatic instrument
moving coil instrument
any of the above
ANSWER : : induction instrument
84.Standard resistor is made from
platinum
maganin
silver
nichrome
ANSWER : : maganin
85.The gravity controlled instrument has crowded scale because current is proportional to
balancing weight
deflection angle
sine of deflection angle
sine of deflection angle
ANSWER : A sensitive galvanometer produces large deflection for a
86.Alternating current is measured by
induction ammeter
permanent magnet type ammeter
electrostatic ammeter
moving iron repulsion type voltmeter
ANSWER : : induction ammeter
87.A multirangq instrument has
multiple shunt or series resistances inside the meter
multicoii arrangement
variable turns of coil
multi range meters inside the measurement system
ANSWER : : multiple shunt or series resistances inside the meter
88.Most sensitive galvanometer is
elastic galvanometer
vibration galvanometer
Duddlb galvanometer
spot ballistic galvanometer
ANSWER : : spot ballistic galvanometer
89.E.m.f. of a Weston cell is accurately measured by
electrostatic voltmeter
hot wire voltmeter
isothermal voltmeter
electrodynamic voltmeter
ANSWER : : electrostatic voltmeter
90.Commonly used standard capacitor is
spherical type
concentric cylindrical type
electrostatic type
multilayer parallel plate type
ANSWER : : concentric cylindrical type
91.The power of a n-phase circuit can be measured by using a minimum of
(n – 1) wattmeter elements
n wattmeter elements
(n + 1) wattmeter elements
2n wattmeter elements
ANSWER : : (n – 1) wattmeter elements
92.Which of the following is measured by using a vector voltmeter ?
Amplifier gain and phase shift
Filler transfer functions
Complex insersion loss
All of the above
ANSWER : : All of the above
93.If an instrument has cramped scale for larger values, then it follows
square law
logarithmic law
uniform law
none of the above
ANSWER : : logarithmic law
94.To measure radio frequency, the suitable frequency meter is
Weston frequency meter
reed vibrator frequency meter
hetrodyne frequency meter
electrical resonance frequency meter
ANSWER : : hetrodyne frequency meter