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ECE :: Measurements and Instrumentation

  1. A capacitance transducer can be used to measure

  2. A.
    thickness of sheet
    B.
    displacement
    C.
    level of fluids
    D.
    all of the above

  3. The dynamometer principle can be used for

  4. A.
    ammeter only
    B.
    voltmeter only
    C.
    wattmeter only
    D.
    ammeter, voltmeter and wattmeter

  5. Assertion (A): In hot wire instrument the material of hot wire in generally platinum iridium.

    Reason (R): A hot wire ammeter is suitable for ac only

  6. A.
    Both A and R are true and R is correct explanation of A
    B.
    Both A and R are true but R is not correct explanation of A
    C.
    A is true R is false
    D.
    A is false R is true

  7. The scale of hot wire ammeter is

  8. A.
    linear
    B.
    non-linear
    C.
    cramped
    D.
    absolute linear

  9. A moving coil meter has a shunt of 0.02 Ω resistance. If coil resistance is 1000 Ω and a potential difference of 500 mV is required across it to cause full scale deflection, the current through shunt is

  10. A.
    2.5 A
    B.
    25 A
    C.
    0.25 A
    D.
    0.025 A

  11. Consider the following features of an instrument

    1. suitable for both ac and dc
    2. free from hysteresis and eddy current errors
    3. No waveform and frequency errors
    4. it is essentially a voltmeter
    This instrument is

  12. A.
    moving iron
    B.
    moving coil
    C.
    electrostatic
    D.
    dynamometer

  13. Which one of the following effects is used in measuring power?

  14. A.
    Seeback
    B.
    Ferrari
    C.
    Induction
    D.
    Hall

  15. The effect of lead resistance is important in measurement of

  16. A.
    resistance of shunt
    B.
    resistance of shunt winding
    C.
    resistance of ammeter
    D.
    both (a) and (c)

  17. A high resistance was measured by loss of charge method. The voltmeter resistance was 1010 ohms. The calculation gave the value of unknown resistance as 0.8 x 109 ohms. The true value of resistance is

  18. A.
    0.8 x 109 Ω
    B.
    less than 0.8 x 109 Ω
    C.
    more than 0.8 x 109 Ω
    D.
    either (b) or (c)

  19. A resistance wire strain gauge has gauge factor 2. If stress is 100 mega newton/m2 and Young's modulus is 200 giga newton/ m2, the percentage change in gauge resistance due to stress is

  20. A.
    0.1
    B.
    0.2
    C.
    0.4
    D.
    0.5