Q.1

In a Ballistic galvanometer

  • inertia is small and damping is also small
  • inertia is large and damping is critical
  • inertia is large and damping is small
  • both inertia and damping are large
Q.2

Panel type instruments are used in

  • power stations
  • automobiles
  • industries
  • all of the above
Q.3

Assertion (A): The speed of a shaft can be measured by using a dc tacho generator.

Reason (R): A two phase servometer can also be used as a speed transducer.

  • 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.4

Which is the displacement transducer with excellent sensitivity, linearity and resolution?

  • Incremental encoder
  • Absolute encoder
  • LVDT
  • Strain gauge
Q.5

The advantage of semiconductor strain gauge over resistance strain gauge is

  • it is more sensitve
  • it is more linear
  • it is less temperature dependent
  • it is cheaper
Q.6

In a phase shifting transformer the currents in the two stator winding are in phase.

  • True
  • False
Q.7

The scale of thermocouple instrument is linear.

  • True
  • False
Q.8

The pointer of an indicating instrument should be

  • very light
  • very heavy
  • neither heavy nor light
  • heavy
Q.9

The electromagnets of an induction wattmeter

  • are laminated
  • are not laminated
  • may be laminated
  • must not be laminated
Q.10

In a vibrating reed frequency meter the natural frequency of two adjacent reeds have a difference of

  • 0.25 Hz
  • 0.5 Hz
  • 1.25 Hz
  • 1 Hz
Q.11

In low power factor wattmeter, the pressure coil is connected

  • to the supply side of current coil
  • to the load side of current coil
  • in either (a) or (b)
  • across the mains
Q.12

Burden of an instrument transformer is expressed in

  • A
  • V-A
  • Ω
  • watt
Q.13

It is required to measure a low magnitude high frequency current. The proper instrument is

  • moving iron
  • dynamometer
  • thermocouple
  • induction
Q.14

A Q meter uses the principle of

  • variation of self inductance
  • variation of mutual inductance
  • series resonance
  • none of the above
Q.15

Magnetic flux can be measured by

  • capacitive pick up
  • inductive pick up
  • resistive pick up
  • hall effect pick up
Q.16

The signal to noise ratio in telemetry should be better than

  • 5 db
  • 10 db
  • 25 db
  • 60 db
Q.17

Two resistances are R1 =±and R2 =± 5%. If they are connected in parallel, the limiting error in percent will be

  • 5%
  • 10%
  • 15%
  • 20%
Q.18

Which of the following devices should be used for accurate measurement of a low dc voltage?

  • Small range moving coil voltmeter
  • Dc potentiometer
  • Small range thermocouple voltmeter
  • Hot wire instrument
Q.19

Bridge circuits using RTD in temperature measurement usually employ 3 lead system so as to obtain

  • higher sensitivity
  • better impedance matching
  • compensation for signal wire resistance
  • reduction in power consumption
Q.20

The numbers of accelerating anodes in a CRO is

  • 1
  • 2
  • 3
  • 4
Q.21

It is required to measure pressure using LVDT. The additional device needed is

  • strain gauge
  • pitot tube
  • bourden tube
  • rotameter
Q.22

If low pressure of 10-6 mm of Hg is required to be measured, we should use

  • compound pressure gauge
  • thermocouple vacuum gauge
  • Pirani gauge
  • ionization type vacuum gauge
Q.23

For measuring current at a high frequency we should use

  • moving iron instrument
  • electrostatic instrument
  • thermocouple instrument
  • moving coil instrument
Q.24

The operating voltage of a megger is about

  • 100 V
  • 12 V
  • 6 V
  • 1 V
Q.25

In semiconductor strain gauge

  • resistance increases with strain
  • resistance decreases with strain
  • resistance increases with strain in p type and decreases with strain in n type
  • resistance increases with strain in n type and decreases with strain in p type
Q.26

Assertion (A): Electrodynamic instrument is not used as ammeter or voltmeter.

Reason (R): Electrodynamic instrument is more costly than PMMC and moving iron instrument.

  • 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.27

Gauge factor of a strain gauge is

  • unit change in resistance per unit change in length
  • change in resistance per unit change in length
  • unit change in length per unit change in resistance
  • none of the above
Q.28

To measure an emf by dc potentiometer it is necessary to standardise the potentiometer with the help of a standard cell.

  • True
  • False
Q.29

Assertion (A): The sign and magnitude of displacement can be measured by an LVDT.

Reason (R): LVDT is based on the principle of mutual inductance.

  • 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.30

If σ is standard deviation, variation is

  • σ - 1
  • σ1.5
  • σ2
  • σ3
Q.31

The stator of phase shifting transformer for use in conjunction with an ac potentiometer has a

  • single phase winding
  • two phase winding
  • 3 phase winding
  • either (a) or (c)
Q.32

Consider the following statements regarding phase sensitive detector

  1. The detector reads zero when phases of input signal and reference signal are different.
  2. The detector acts as a linear rectifier.
  3. The detector can be used as vector voltmeter.
Of the above statements which are correct?
  • 1, 2, 3
  • 1 and 2
  • 2 and 3
  • 1 and 3
Q.33

Which of the following quantities have same dimension in emu and esu?

  1. Current
  2. Electrical power
  3. Electrical energy
Select the answer as per following codes
  • 1 only
  • 1 and 2
  • 2 and 3
  • 1 and 3
Q.34

In a dynamometer instrument, the moving coil is pressure coil.

  • True
  • False
Q.35

A transducer must have

  • good dynamic response
  • good sensitivity
  • good resolution
  • all of the above
Q.36

A moving iron instrument can be used for dc as well as ac.

  • True
  • False
Q.37

Two wattmeter method of 3-phase power measurement can be used to find

  • total active power
  • total active power and power factor
  • total active power and reactive power
  • total active power, power factor, apparent power, and reactive power
Q.38

An ohmmeter is a

  • moving coil instrument
  • moving iron instrument
  • dynamometer instrument
  • induction instrument
Q.39

Four terminal approach is used in measuring low resistance because it

  • eliminates thermoelectric energy
  • eliminates stray capacitance
  • eliminates stray inductance
  • eliminates the effect of leads and contacts
Q.40

Consider the following statements regarding electro-dynamometer type indicating instrument
It can be used for measuring

  1. Direct current
  2. Alternating current
  3. Direct voltage
  4. Alternating voltage
Of these statements
  • 1 and 2 are corect
  • 3 and 4 are correct
  • 1 and 3 are correct
  • 1, 2, 3, 4 are correct
Q.41

An ac bridge uses galvanometer as detector.

  • True
  • False
Q.42

Assertion (A): Capacitance effect can be used to measure thickness of sheets, displacement and pressure.

Reason (R): Capacitance between two plates depends on the area of plates, distance between plates and permittivity of medium.

  • 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.43

Which of the following transformers has low primary current?

  • Current transformer
  • Potential transformer
  • Distribution transformer
  • Both (a) and (b)
Q.44

In Maxwell's bridge the unknown inductance is measured by comparing it with a standard capacitor.

  • True
  • False
Q.45

An electrodynamometer instrument has the advantage of

  • freedom from hysteresis and eddy currents because air cored coils are used
  • freedom from hysteresis and eddy currents because cores of coils have special ferromagnetic material
  • high torque/weight ratio
  • low cost
Q.46

In a Weston synchronoscope, the moving coil is connected across

  • bus bar
  • incoming alternator
  • lamp
  • fixed coils
Q.47

Load cell uses

  • piezoelectric crystal
  • capacitor
  • mutual inductance
  • strain gauge
Q.48

If two time varying signals of equal magnitude and zero phase displacement are applied to X and Y plates respectively; of CRO, the display will be

  • a straight line
  • a circle
  • an ellipse
  • a square
Q.49

The multiplier resistance and meter coil in a voltmeter are in

  • series
  • parallel
  • series-parallel
  • either (a) or (b)
Q.50

Assertion (A): Double Kelvin's bridge is used to measure low resistances.

Reason (R): In low resistance, the contact and lead resistances are very important.

  • 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
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