Q.1

The sensitivity of electromagnetic digital flow meter can be increased by increasing

  • circumferential width of rotor teeth
  • radial depth of rotor teeth
  • thickness of rotor teeth
  • number of teeth
Q.2

Assertion (A): If the reading of an instrument is low, the error is large.

Reason (R): The error of an instrument is certain percentage of its full scale deflection.

  • 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
Q.3

A thermocouple instrument can be used over a very wide frequency range.

  • True
  • False
Q.4

For a current transformer, the standard secondary rating is

  • 1 A or 5 A
  • 2.5 A
  • 10 A
  • 5 A or 10 A
Q.5

In ac bridge measurements, 'Wagner ground' means

  • a special RC connection to eliminate stray magnetic effects
  • a special RC connection to eliminate stray capacitance effects
  • an unwanted and unintended ground connection
  • a large metal plate buried in ground connected to one corner of bridge
Q.6

If temperature increases by about 50°, the resistance of thermistor changes to

  • half of its initial value
  • twice of its initial value
  • eight times of its initial value
  • one eight of its initial value
Q.7

To measure dielectric loss you would use

  • Anderson bridge
  • Kelvin bridge
  • Schering bridge
  • Maxwell's bridge
Q.8

Minute cracks in metals and minute faults in welded joints can be detected using

  • IR rays
  • UV rays
  • a rays
  • X-ray/γ-rays
Q.9

The increase in intensity of trace in a CRO causes a change in

  • beam current
  • frequency of time base
  • gain of Y amplifier
  • accelerating voltage
Q.10

A vibration galvanometer is a

  • moving coil instrument
  • moving iron instrument
  • dynamometer instrument
  • induction instrument
Q.11

Consider the following statements about mutual inductances:

  1. The value should remain constant under all conditions.
  2. The mutual inductance should not vary with temperature.
  3. The inductance should be independent of excitation.
  4. They have two coils wound on a bobbin of hard magnetic material, coils being separated by a range.
Out of the above, correct statement are
  • 2, 3, 4
  • 1, 2, 3
  • 1, 3, 4
  • 1, 2, 4
Q.12

Which of the following draws minimum power from source?

  • PMMC
  • Electronic voltmeter
  • Electrostatic voltmeter
  • Moving iron voltmeter
Q.13

A diode peak reading VTVM and thermocouple meter are connected across output of an amplitude modulated circuit. In the absence of modulation both meters readV. When sinusoidal AM is applied, VTVM readsThe reading of thermocouple meter will be

  • 10 V
  • 12.5 V
  • 14.1 V
  • 15 V
Q.14

The sensitivity of a potentiometer can be increased by

  • increasing the length of wire
  • decreasing the length of wire
  • increasing the current in the wire
  • decreasing the current in the wire
Q.15

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
Q.16

The resistance of resistance strain gauge is about

  • 5 Ω
  • 50 Ω
  • 120 Ω
  • 0.5 Ω
Q.17

Consider the following statements about mutual inductances:

  1. The value should remain constant under all conditions.
  2. The mutual inductance should not vary with temperature.
  3. The inductance should be independent of excitation.
  4. They have two coils wound on a bobbin of hard magnetic material, coils being separated by a range.
Out of the above, correct statement are
  • 2, 3, 4
  • 1, 2, 3
  • 1, 3, 4
  • 1, 2, 4
Q.18

In ac bridge measurements, 'Wagner ground' means

  • a special RC connection to eliminate stray magnetic effects
  • a special RC connection to eliminate stray capacitance effects
  • an unwanted and unintended ground connection
  • a large metal plate buried in ground connected to one corner of bridge
Q.19

Which of these instruments is dynamometers type?

  • Wattmeter
  • Power factor meter
  • Frequency meter
  • Both (a) and (b)
Q.20

The instrument used to check insulation of household wiring is

  • megger
  • ohmmeter
  • multimeter
  • high resistance voltmeter
Q.21

Watthour meter is an integrating instrument

  • True
  • False
Q.22

An ammeter is

  • secondary instrument
  • absolute instrument
  • recording instrument
  • integrating instrument
Q.23

It is required to measure temperature in the range of 1300-1520°C. The most suitable thermocouple is

  • chromel constantan
  • iron constantan
  • chromel aluminium
  • platinum-rhodium
Q.24

A megger has a hand driven dc generator.

  • True
  • False
Q.25

In a CRO, the time base signal is applied to

  • X plates
  • Y plates
  • either X or Y plates
  • alternately X and Y plates
Q.26

Which bridge can be used to measure frequency?

  • Maxwell
  • Kelvin
  • Schering
  • Wein
Q.27

The difference between measured value and true value is called

  • gross error
  • relative error
  • probable error
  • absolute error
Q.28

In a single phase power factor meter the phase difference between currents in the two pressure coils is

  • exactly 0°
  • approximate 0°
  • exactly 90°
  • approximate 90°
Q.29

A hot wire instrument is not affected by stray magnetic fields.

  • True
  • False
Q.30

Assertion (A): A ballistic galvanometer is used to measure charge.

Reason (R): In a flux meter, the damping is large.

  • 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
Q.31

Schering bridge operates at a high voltage of aboutkV.

  • True
  • False
Q.32

Which of these instrument does not have a control spring?

  • Moving iron ammeter
  • PMMC ammeter
  • Electrostatic voltmeters
  • Power factor meter
Q.33

The time base generator in a CRO gives an output which is

  • low frequency sinusoidal
  • high frequency sinusoidal
  • low frequency rectangular
  • high frequency sawtooth
Q.34

A digital voltmeter can count from 0 toIf full scale reading is 9.V, the resolution of full scale reading is

  • 0.001
  • 1000
  • 2 digit
  • 1 mV
Q.35

In air friction damping

  • the air pressure opposes the motion of piston when it is moving inwards
  • the air pressure opposes the motion of piston when it is moving outwards
  • the air pressure opposes the motion of piston both when it is moving inwards as well as outwards
  • the air pressure may oppose or aid the motion of piston depending on the design
Q.36

Pirani gauge is used to measure

  • very low pressure
  • high pressure
  • pressure in the range of 1 atmosphere
  • fluid flow
Q.37

In an ac coordinate potentiometer, the currents inphase and quadrature potentiometer are adjusted to be

  • out of phase by 90°
  • in phase
  • out of phase by 45°
  • out of phase 180°
Q.38

Both X and Y plates of a CRO are excited by ac signals. The display is an ellipse which makes one rotation in 5 seconds. This means that

  • the frequency of one input is 5 times that of other
  • the difference between the frequencies of the two signals is one fifth of hertz
  • the difference between the frequencies of the two signals is 5 Hz
  • either (a) or (c)
Q.39

Assertion (A): A transducer needs an output measuring or display device for measuring a non electrical quantity.

Reason (R): In some transducers the output voltage is too small and needs amplification before it can be measured.

  • 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
Q.40

A permanent magnet moving coil measures

  • true rms value
  • dc value
  • peak value
  • rms plus dc value
Q.41

In Weston frequency meter, the magnetic axes of the two fixed coils are

  • parallel
  • perpendicular
  • inclined at 60°
  • inclined at 15°
Q.42

The switch board instruments

  • should be mounted in vertical position
  • should be mounted in horizontal position
  • should be mounted at about 45°
  • should be mounted at about 80°
Q.43

Radiation pyrometer is used to measure temperature in the range of

  • -200 to 500° C
  • 0 to 500° C
  • 500 to 1200° C
  • 1200 to 2500° C
Q.44

An average responding rectifier type electronic voltmeter has its scale calibrated in terms of rms value of sine wave. IfV peak value square wave is fed to this voltmeter, the reading will be

  • 111 V
  • 100 V
  • 90.9 V
  • 70.7 V
Q.45

The most serious problems in ac bridge measurement is

  • eddy currents
  • leakage current
  • residual magnetism
  • stray fields
Q.46

Assertion (A): An electrostatic voltmeter is free from hysteresis and eddy current errors.

Reason (R): An electrostatic voltmeter has a number of fixed and moving vanes in parallel.

  • 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
Q.47

In indicating instruments the controlling torque is provided by a spring.

  • True
  • False
Q.48

For measuring a very high resistance we should use

  • Kelvin's double bridge
  • Wheatstone bridge
  • Meggar
  • Either (a) or (c)
Q.49

Assertion (A): CRT is the most important component of a CRO.

Reason (R): When an electron beam strikes the screen of CRT, a spot of light is produced.

  • 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
Q.50

A capacitance transducer has two plates each of area 5 mm2. The coil gap is 2 mm. Displacement sensitivity due to change in gap length is

  • 11.1 pF/cm
  • 44.2 pF/cm
  • 52.3 pF/cm
  • 66.3 pF/cm
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