For use atHz the range of scale of vibrating reed frequency meter is
-
25 - 75 Hz -
40 - 60 Hz -
47 - 53 Hz -
42 - 58 Hz
A current of 3.A is flowing through a resistance of 34.Ω. The voltage drop across resistance to the appropriate number of significant figures is
-
113.685 V -
113.68 V -
113.6 V -
114 V
Assertion (A): An RTD uses platinum coil.
Reason (R): Platinum is a very stable material.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
Which of the following, is not a piezoelectric material?
-
Rochelle salt -
Quartz -
Lithium sulphate -
Sodium bicarbonate
Assertion (A): In two wattmeter method of 3 phase power measurement, one of the wattmeters would read negative if power factor of load is less than 0.5.
Reason (R): In two wattmeter method of 3 phase power measurement, both the wattmeters would show equal readings if power factor of load is unity.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
In a low power factor wattmeter, the resistance of pressure coil is more than in ordinary wattmeter.
-
True -
False
The precision of an instrument indicates its ability to reproduce a certain reading with a given
-
drift -
resolutions -
shift -
consistency
Assertion (A): A radiation pyrometer is very suitable for high temperature measurement.
Reason (R): When temperature is high, a physical contact between hot body and thermometer is not desirable.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
A universal RLC bridge uses
-
Maxwell bridge for measurement of inductance and De Sauty's bridge for measurement of capacitance -
Maxwell's bridge for measurement of inductance and modified De Sauty bridge for measurement of capacitance -
Maxwell Wien bridge for measurement of inductance and modified De Sauty bridge for measurement of inductance -
Maxwell Wien bridge for measurement of inductance and Wien bridge for measurement of capacitance
If φsh is flux of shunt magnet, φse is flux of series magnet, ish is eddy current due to φse, the torque in an induction wattmeter is proportional to
-
φse ise + φsh ish -
φsh ise - φse ish -
φsh ish - φse ise -
φsh ish + φse ise
In 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
When deflecting torque and braking torque in an energy meter are zero,
-
the disc rotates at steady speed -
the disc is stationary -
the disc accelerates -
the disc retards
During testing of an energy meter, the energy recorded by meter was 0.kWh and correct energy was found to be 0.kWh. The error and correction respectively are
-
-0.01 kWh and 0.01 kWh -
0.01 kWh and -0.01 kWh -
-0.01 kWh and ± 0.01 kWh -
± 0.01 kWh and 0.01 kWh
Two resistances are : R1 =Ω ± 1.Ω and R2 =Ω ± 3.Ω. The sum R1 + R2 along with limiting error is
-
111 Ω ± 1.8 Ω -
111 Ω ± 3.75 Ω -
111 Ω ± 5.55 Ω -
111 Ω ± 1.95 Ω
Consider the following statements about a moving iron instrument
- It is an unpolarised instrument.
- It has permanent magnet.
- It has a fixed coil.
- It has two iron vanes.
-
1, 2, 3 are correct -
1, 2, 4 are correct -
1, 3 and 4 are correct -
2, 3, 4 are correct
The braking torque in single phase energy meter is proportional to speed of disc.
-
True -
False
To measure a resistance by a dc potentiometer
-
it is necessary to standardise the potentiometer -
it is not necessary to standardise the potentiometer -
it is necessary to use a volt ratio box -
none of the above
Harmonic distortion analyser
-
measures amplitude of each harmonic -
measures rms value of fundamental frequency component -
measures rms value of all harmonics except fundamental frequency -
displays rms value of each harmonic on screen of CRO
In a megger the moving coil meter has a permanent magnet.
-
True -
False
The moving iron instruments are generally repulsion type.
-
True -
False
If C is spring constant and θ is deflection, controlling torque is
-
Cθ -
C/θ -
θ/C -
C2θ
A generated voltage is equally dependent on three resistances R1, R2, R3 and its value is V = (R1R2)/R3. If tolerance of each resistor is 0.1%, the maximum error in voltage is
-
0.3% -
± 0.3% -
0.1% -
± 0.1%
The sensitivity of a voltmeter using 0-5 mA meter movement is
-
50 Ω/V -
100 Ω/V -
200 Ω/V -
500 Ω/V
An instrument of accuracy class 1 can have an error equal to
-
+ 1% of reading -
± 1% of reading -
± 1% of full scale deflection -
+ 1% of full scale deflection
The two pressure coils in a single phase power factor meter of turns
-
the same dimension and the same numbers of turns -
the same dimension but different number of turns -
different dimension and different numbers of turns -
different dimension but the same numbers of turns
Piezoelectric effect can be used to measure
-
force -
strain -
acceleration -
all of the above
In dc tacho generators used for measurement of speed of shaft, frequent calibration is necessary because
-
contacts wear off -
strength of permanent magnet decreases with age -
armature current produces heating effect -
there is back emf
A multimeter can be used as ohmmeter.
-
True -
False
Rayleigh current balance is an absolute instrument.
-
True -
False
Assertion (A): A thermocouple transducer is based on Seeback effect.
Reason (R): In a thermocouple transducer used for temperature measurement, the cold junction is usually kept in ice bath.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
In an Anderson bridge the unknown inductance is measured in terms of
-
known inductance and resistance -
known inductance -
known capacitance and resistance -
known capacitance
Assertion (A): The scale a PMMC ammeter is linear.
Reason (R): The deflecting torque of PMMC is proportional to current in the coil.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
A voltage of aboutV dc can be measured
-
directly by dc potentiometer -
by dc potentiometer in conjunction with a volt ratio box -
a dc potentiometer in conjunction with a known resistance -
both (b) and (c)
Assertion (A): If the resistance of shunt of an ammeter is increased, the range of ammeter is reduced.
Reason (R): If the series resistance of a voltmeter is increased, the range of voltmeter is increased.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
In figure, C0 is distributed capacitance and C is tuning capacitor. If C = C1 for fundamental frequency and C = C2 for second harmonic, then C0 = 
-
-
-
-
C1 - 2C2
Two meters X and Y requiremA andmA for full scale deflection. Then
-
X is more sensitive -
Y is more sensitive -
both are equally sensitive -
it is not possible to determine from given data
A dual trace CRO has
-
one electron gun -
two electron guns -
one electron gun with one two pole switch -
two electron guns with one two pole switch
A current of 3.A is flowing through resistance of 35.Ω. The voltage drop across resistance to the appropriate number of significant figures is
-
113.4624 V -
113.462 V -
113.46 V -
113 V
Assertion (A): Moving iron instrument can be used on ac or dc.
Reason (R): In a moving iron instrument deflecting torque is proportional to square of current.
-
Both A and R are true and R is correct explanation of A -
Both A and R are true but R is not correct explanation of A -
A is true R is false -
A is false R is true
In a low power factor wattmeter, compensation for pressure coil current is provided.
-
True -
False
Two sinusoidal signals of equal amplitude and frequency are applied to X and Y plate of CRO respectively. The observed Lissajous pattern is a straight line. The phase shift between signals is
-
zero -
90° -
either zero or 180° -
either 90° or 270°
For measuring mutual inductance we can use
-
Anderson bridge -
Maxwell's bridge -
Heaviside bridge -
Either (a) or (b)
Which instrument needs creep compensation?
-
Dynamometer wattmeter -
Induction wattmeter -
Energy meter -
Both (b) and (c)
A land line telemetry system is suitable for distance upto
-
about 1 km only -
about 10 km only -
about 100 km only -
any of the above
De Sauty bridge is very widely used due to
-
simplicity -
perfect balance for imperfect capacitor -
perfect balance for air capacitors -
maximum sensitivity
The scale of a dynamometer is linear when used as
-
ammeter -
voltmeter -
wattmeter -
both (a) and (c)
The moving iron instruments are generally repulsion type.
-
True -
False
Use of high permeability core in moving iron instrument helps in
-
reducing size of meter -
increasing sensitivity -
reducing temperature error -
all of the above
The resistance of series field winding is a low resistance.
-
True -
False
A Weston synchronoscope is a
-
moving coils instrument -
moving iron instrument -
dynamometer instrument -
induction instrument