Measurement of non-electrical quantity involves the following subsystems
- Amplifier block
- Display block
- Instrumentation block
- Transducer block
-
4, 1, 3, 2 -
4, 3, 1, 2 -
1, 3, 2, 4 -
1, 2, 3, 4
A linear displacement digital transducer generally uses
-
straight binary code -
BCD -
gray code -
hexadecimal code
Magnetic effect of current is used in
-
ammeters -
voltmeters -
wattmeters -
ammeters, voltmeters, wattmeters and energy meters
In a resistance strain gauge, G =stress =kg/cm2, R =Ω. The value of ΔR will be
-
2 Ω -
3 Ω -
4 Ω -
1 Ω
In figure the values of Rx and Cx are 
The term 'Poisson's ratio' is connected with
-
strain gauge -
LVDT -
Bourden tube -
capacitance transducer
A dynamometer wattmeter is connected in ac circuit. The measured power is
-
rms power -
average power -
peak power -
instantaneous power
Which of the following measurements using a dc potentiometer do not require standardisation of potentiometer?
-
Measurement of unknown voltage -
Measurement of resistance -
Measurement of unknown current -
Calibration of voltmeter
Which of the following are needed both for protection and metering?
-
Wattmeters -
Instrument transformers -
Energy meters -
Power factor meters
Magnetic flux density has the dimensions
-
MI-1T-2 -
M-1I-2T-2 -
ML-3T-2 -
MI-1T-3
Loss of charge method is suitable for medium resistances.
-
True -
False
In two wattmeter method of 3 phase power measurement, when does one wattmeter read negative
-
when power factor is less than 0.5 lagging -
when power factor is greater than 0.5 lagging -
when power factor is less than 0.5 -
when power factor is unity
Which of the following statement is correct for two wattmeters method of power measurement in 3 phase circuit?
-
Power can be measured by this method only for star connected loads -
When two wattmeters have equal readings power factor is 0.5. -
When power factor is 1, one of the wattmeters readings is zero -
When the two wattmeter read equal and opposite, p.f. is zero.
A digital frequency counter can be converted to DVM by addition of a suitable
-
voltage controlled oscillator -
D/A converter -
power amplifier -
operational amplifier
A meter with a resistance ofΩ and a full scale deflection of current of 1 mA is to be converted into voltmeter of 0 - 5 V range. The multiplier resistance should be
-
490 Ω -
5000 Ω -
4900 Ω -
5100 Ω
It is required to measure angular position. Out of the transducers
- Circular potentiometer
- LVDT
- E pick up
- Synchro
-
1, 2, 3, 4 -
2 and 3 -
1, 2, 4 -
1 and 4
In a thermocouple temperature transducer, the output voltage is usually measured by
-
high resistance ammeter -
high resistance voltmeter -
high resistance milli-voltmeter -
none of the above
A dynamometer wattmeter is connected in ac circuit. The reading will be
-
V-A product -
average power -
peak power -
instantaneous power
The household energy meter is
-
indicating instrument -
recording instrument -
integrating instrument -
none of the above
A moving iron instrument gives correct reading when used at
-
low frequencies -
high frequencies -
only one frequency -
all frequencies upto a certain value
The speed transducer using a drag cup rotor has the main advantage of
-
very high accuracy -
low energy requirement -
cheap construction -
all of the above
A voltmeter using thermocouples measures
-
rms value -
peak value -
average value -
peak to peak value
A standard cell of 1.V is used with a slide wire potentiometer. The balance was obtained atcm. When an unknown emf was connected, the balance was obtained atcm. The magnitude of unknown emf is
-
1.39 V -
0.75 V -
13.9 V -
7.45 V
Induction wattmeter can be used in
-
ac circuit only -
dc circuit only -
both ac and dc circuit -
ac 3 phase only
Assertion (A): Wien bridge can be used for measuring frequency.
Reason (R): A frequency meter forHz system has a frequency range oftoHz.
-
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
Consider the following operation in respect of Wheatstone bridge (Kb, denotes battery key, Kg denotes galvanometer key)
- open Kb
- close Kg
- close Kb
- open Kg
-
1, 2, 3, 4 -
3, 1, 2, 4 -
4, 3, 2, 1 -
3, 2, 4, 1
The power input and output in a device areW andW with each reading in doubt by ±W. The percentage uncertainty in losses is
-
± 7.55% -
± 3.77% -
± 11.32% -
± 15.09%
If eddy current damping is to be used, the disc of instrument should be
-
non-conducting and non-magnetic -
conducting and magnetic -
conducting and non-magnetic -
non-conducting and magnetic
Which of these has poor overload capacity?
-
PMMC instrument -
Hot wire instrument -
Dynamometer instrument -
Both (a) and (c)
Two voltmeters 0-V each having resistances of 5 kΩ andkΩ respectively and are connected in series. To ensure that neither of them goes beyond scale the total voltage which can be applied should be less than
-
500 V -
400 V -
375 V -
250 V
A meter coil has a resistance ofΩ and a full scale deflection current ofmA. To convert it into a voltmeter of 0-V range, the series resistance should be
-
20 kΩ -
19.9 kΩ -
1.9 kΩ -
20.1 kΩ
Which of these has a magnetic brake?
-
Thermocouple ammeter -
Energy meter -
Dynamometer wattmeter -
Frequency meter
The volt ratio box is basically a
-
potential divider -
current transformer -
a high resistance voltmeter -
either (a) or (c)
A sinusoidal ac voltage of amplitudeV is applied to a rectifying device which offersΩ resistance in forward direction and infinite resistance in backward direction. A moving coil ammeter is also connected in the circuit. The reading of ammeter will be
-
10 A -
5 A -
3.185 A -
14.14 A
In figure the bridge is balanced when Z4 is 
-
120∠70° -
187.5∠ - 10° -
187.5∠ - 70° -
333.3∠ - 70°
The scale of moving iron instrument is linear.
-
True -
False
LVDT is a
-
pressure transducer -
displacement transducer -
velocity transducer -
acceleration transducer
In 3 phase power measurement by two wattmeter method, both wattmeters had equal reading. The power factor of load is
-
1 -
0.5 lagging -
0.5 leading -
0
Amm long conductor has a resistance ofΩ. The change in resistance is 13.3 Ω and change in length is 1.6 mm under tension. The gauge factor is
-
1.2 -
1.6 -
2.1 -
2.6
Two numbers are± 5 and±The sum of the numbers with range of doubt is
-
760 ± 8 -
760 ± 2 -
760 + 8 -
760 - 8
Assertion (A): Schering bridge is a low voltage bridge.
Reason (R): Schering bridge is very commonly used for measurement of capacitance.
-
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 variable reluctance tachometer hasteeth on rotor. The speed of shaft on which it is mounted inrpm. The frequency of output pulses is
-
1800 per second -
3600 per second -
4800 per second -
5600 per second
With a variable reluctance tachometer havingrotor teeth the count readscounts per minute. The speed in RPM is
-
36 -
60 -
360 -
3600
When measuring phase angle between two waves using a CRO, the time base generator is connected to
-
X plate -
Y plate -
both X and Y plate -
neither X nor Y plates
A 0-V voltmeter has an accuracy of 0.of full scale reading. If voltage measured isV, the error is
-
3% -
2% -
1.5% -
.75%
In Schering bridge, the potential of detector above earth potential is about
-
a few volts -
10 kV -
1000 V -
either (a) or (b)
Which instrument is based on induction principle?
-
Dynamometer wattmeter -
Induction wattmeter -
Energy meter -
Both (b) and (c)
Measuring of unknown voltage with a dc potentiometer loses its advantage of open circuit measurement when
-
primary circuit battery is changed -
standardisation is done to compensate for drift -
voltage is larger than range of potentiometer -
range reduction by factor of 10 is employed
It is required that a strain gauge has gauge factor ofThe proper strain gauge is
-
constantan strain gauge -
nichrome strain gauge -
semiconductor strain gauge -
alloy strain gauge
The dimensions of EMF are
-
ML2I-1T-3 -
M-1T-3 -
ML2I-2T-3 -
ML3I-1T-3