Q.1

Four voltmeters have following specifications. If accuracy is main consideration which is the best?

  • 100 V, 2 mA
  • 100 V, 100 mA
  • 100 V, 1 mA
  • 100 V, 0.1 mA
Q.2

Figure shows a Wheatstone bridge with RTD to one arm. If resistance of RTD =Ω, the voltage V0 is

  • 49 mV
  • 51 mV
  • 48 mV
  • 45 mV
Q.3

Figure shows a Wheatstone bridge with RTD to one arm. If resistance of RTD =Ω, the voltage V0 is

  • 49 mV
  • 51 mV
  • 48 mV
  • 45 mV
Q.4

Figure shows a Wheatstone bridge with RTD to one arm. If resistance of RTD =Ω, the voltage V0 is

  • 49 mV
  • 51 mV
  • 48 mV
  • 45 mV
Q.5

The ac bridge in figure is balanced. Z1 = 100∠30°, Z2 = 150∠0°, Z3 =-Then Z4 =

  • 375∠70° Ω
  • 375∠ - 70° Ω
  • 150∠0° Ω
  • 150∠20° Ω
Q.6

The Lissajous pattern observed on screen of CRO is a straight line inclined atto x axis. If X-plate input is 2 sin ωt, the Y-plate input is

  • 2 sin ωt
  • 2 sin (ωt + 45°)
  • 2 sin (ωt - 45°)
  • 22 sin ωt + 45°)
Q.7

A moving coil instrument has a resistance of 0.6 Ω and full scale deflection at 0.1 A. To convert it into an ammeter of 0-A range, the resistance of shunt should be

  • 0.6 Ω
  • 0.06 Ω
  • 0.1 Ω
  • 0.004 Ω
Q.8

If reference sound pressure P0 is 2 x 10-5 N/m2, a sound pressure ofdB is equal to

  • 0.632 N/m2
  • 0.707 N/m2
  • 0.835 N/m2
  • 0.925 N/m2
Q.9

The angle δ for a mica capacitor is about

  • 25°
  • 15°
  • 5°
  • 1°
Q.10

In a ballistic galvanometer, a charge ofμC gives a first swing of 25°. The charge required to cause first swing ofis

  • 200 μC
  • 400 μC
  • 50 μC
  • 25 μC
Q.11

To increase Q factor of a coil, the wire should be

  • long
  • thin
  • thick
  • long and thin
Q.12

A moving coil instrument has a resistance of 0.5 Ω and a full scale deflection of 0.1 A. To convert it into an ammeter of 0-A the shunt resistance should be

  • 0.004 Ω
  • 0.005 Ω
  • 0.05 Ω
  • 0.1 Ω
Q.13

A piezoelectric force transducer has a charge sensitivity ofpC/N. It is connected to a charge amplifier and overall gain of transducer and amplifier ismV/N. The gain of amplifier is

  • 1 mV/pC
  • 1.5 mV/pC
  • 2.5 mV/pC
  • 4 mV/pC
Q.14

Which of the following voltmeters would you use for measuring voltage acrosskΩ resistance?

  • Voltmeter having a resistance of 5 kΩ
  • Voltmeter having a sensitivity of 1 kW/V
  • Voltmeter having sensitivity of 10 kW/V
  • None of the above
Q.15

A digital voltmeter has a read out range from 0 tocounts. If the full scale reading is 9.V, the resolution is

  • 1 V
  • 0.01 V
  • 1 mV
  • 1 μV
Q.16

The coil of a moving coil meter hasturns, ismm long andmm wide. The control torque isx 10-6 N-m on full scale. If B = 1 Wb/m2, range of meter is

  • 1 mA
  • 2 mA
  • 3 mA
  • 4 mA
Q.17

Two resistors R1 =Ω ±and R2 =Ω ±are connected in series. The total resistance is

  • 111 ± 0 Ω
  • 111 ± 2.778 Ω
  • 111 ± 5.55 Ω
  • 111 ± 7.23 Ω
Q.18

An ammeter of 0-A range has a guaranteed accuracy ofof full scale reading. The current measured is 5 A. The limiting error is

  • 2%
  • 2.5%
  • 4%
  • 5%
Q.19

The coil of a moving iron instrument has a resistance ofΩ and an inductance of 1 H. It readsV when aV dc is applied. If series resistance isΩ, its reading when fed byV,Hz ac will be

  • 260 V
  • 252 V
  • 250 V
  • 248 V
Q.20

Potentiometer method of dc voltage measurement is more accurate than direct measurement using a voltmeter because

  • it loads the circuit to maximum extent
  • it loads the circuit moderately
  • it does not load the circuit at all
  • it uses centre zero galvanometer instead of Voltmeters
Q.21

An LVDT is used to measure displacement. The LVDT feeds a Voltmeter of 0-5 V range through again amplifier. For a displacement 0.5 mm the output of LVDT is 2 mV. The sensitivity of instrument is

  • 0.1 V/mm
  • 0.5 V/mm
  • 1 V/mm
  • 5 V/mm
Q.22

A single phase energy meter has the ratingresolutions/ kWh. If aW electric gadget is used for 4 hours, the energy meter will make

  • 1200 revolutions
  • 1800 revolutions
  • 2100 revolutions
  • 2400 revolutions
Q.23

Consider the following statements: In a differential amplifier using JFET, the differential output offset is due to

  1. mismatch between FET parameters
  2. difference in values of resistances used in circuit
  3. variation in supply voltage.
Of the statements, the correct statements are
  • 1 and 2
  • 1, 2, 3
  • 2, 3
  • 1, 3
Q.24

In a strain measuring device using a strain gauge, the output quantity is

  • voltage
  • resistance
  • impedance
  • either (a) or (b)
Q.25

In 3 phase power measurement by two wattmeter method, the reading of one wattmeter is zero. The power factor of load is

  • 1
  • 0.5
  • 0
  • 0.8
Q.26

Assertion (A): A hot wire ammeter has a cramped scale.

Reason (R): The heat 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
Q.27

Assertion (A): When a wattmeter is used for low impedance loads, the pressure coil is connected across the load.

Reason (R): A wattmeter measures apparent power.

  • 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.28

Assertion (A): De sauty's bridge is suitable only for pure capacitor.

Reason (R): Capacitors are mostly perfect.

  • 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.29

In a CRO which of the following is not a part of electron gun

  • cathode
  • grid
  • accelerating anode
  • X - Y plates
Q.30

Which of the following is true about an impulse voltage?

  • It is a unidirectional voltage
  • Chopped impulse flashover does not occur
  • Time taken to rise is equal to time taken to fall
  • RMS value is always less than 50% of average value
Q.31

As per BIS there are 6 accuracy classes of instruments.

  • True
  • False
Q.32

In which of the transformer is the secondary nearly short circuited under normal operating conditions?

  • CT
  • PT
  • Distribution transformer
  • Power transformer
Q.33

In a strain measuring device using a strain gauge, the output quantity is

  • voltage
  • resistance
  • impedance
  • either (a) or (b)
Q.34

Which of the following is true about an impulse voltage?

  • It is a unidirectional voltage
  • Chopped impulse flashover does not occur
  • Time taken to rise is equal to time taken to fall
  • RMS value is always less than 50% of average value
Q.35

In a strain measuring device using a strain gauge, the output quantity is

  • voltage
  • resistance
  • impedance
  • either (a) or (b)
Q.36

A meter having 0-μA range andΩ resistance is required to be changed to 0-mA meter. The value of shunt resistance is about

  • 1 Ω
  • 10 Ω
  • 99 Ω
  • 100 Ω
Q.37

Electrostatic voltmeter is suitable only for low voltages.

  • True
  • False
Q.38

A meter has a square law scale. For 2 A current the deflection in 90°. For a deflection of 45°, the current is

  • 1 A
  • 1.5 A
  • 1.414 A
  • 1.61 A
Q.39

Kelvin's double bridge is used to measure low resistances because

  • it has high sensitivity
  • there is no thermoelectric emf
  • resistance variation due to temperature
  • effect of contact and lead resistances is eliminated
Q.40

A capacitance transducer can be used to measure

  • thickness of sheet
  • displacement
  • level of fluids
  • all of the above
Q.41

Two resistances R1 = 18.7 Ω. and R2 = 3.Ω in series. The total resistance to the appropriate number of significant figures is

  • 22.324 Ω
  • 22.32 Ω
  • 22.3 Ω
  • 22 Ω
Q.42

The loss of charge method can be used to measure

  • resistance of shunt
  • insulation resistance of cable
  • resistance of shunt winding
  • both (b) and (c)
Q.43

Consider the following statements

  1. Thermistor is more sensitive than platinum resistance thermometer
  2. The resistance of thermistor is solely a function of its absolute temperature whether the source of heat is external or internal
  3. Thermistor has linear temperature-resistance relationship
  4. Thermistor has linear negative temperature coefficient
Of the Statements, the correct statements are
  • 1 and 2
  • 3 and 4
  • 1, 2, 3, 4
  • 1, 2 and 4
Q.44

Insertion of a dielectric material between the plates of an air capacitor

  • increases the capacitance
  • decreases capacitance
  • has no effect an capacitance
  • increases breakdown voltage
Q.45

A resistance is measured by voltmeter-ammeter method. The voltmeter is 0-250V, ±accuracy and ammeter is 0-5 A, ± 1 % accuracy. The readings of voltmeter and ammeter areV and 2 A respectively. The error in the measured resistance can be

  • ± 1%
  • ± 2%
  • ± 5%
  • ± 10%
Q.46

An induction wattmeter can be used for

  • dc only
  • 50 Hz ac only
  • both ac and dc
  • high frequency ac only
Q.47

An accelerometer has a seismic mass of 0.kg and spring constant of 3 x 105 N/m. If maximum displacement of mass is ± 1 mm, the maximum acceleration which can be measured is

  • 30 m/s2
  • 60 m/s2
  • 90 m/s2
  • 120 m/s2
Q.48

Consider the following Statements regarding resistance strain gauge

  1. The gauge factor is in the range of 2 to 5.
  2. The resistance changes due to change in specific resistance with strain.
  3. The resistance increases with increase in temperature.
Of the above statements, which are correct?
  • 1, 2, 3
  • 1 and 2
  • 2 and 3
  • 1 and 3
Q.49

Assertion (A): Shunt of an ammeter has a low resistance.

Reason (R): Shunt may be connected in series or in parallel with ammeter.

  • 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

The dynamometer principle can be used for

  • ammeter only
  • voltmeter only
  • wattmeter only
  • ammeter, voltmeter and wattmeter
0 h : 0 m : 1 s