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ECE :: Measurements and Instrumentation

  1. Assertion (A): If the resistance of shunt of an ammeter is increased, the range of ammeter is reduced.

    Reason (R): If the series resistance of a voltmeter is increased, the range of voltmeter is increased.

  2. 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

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  3. Two sinusoidal signals of equal amplitude and frequency are applied to X and Y plate of CRO respectively. The observed Lissajous pattern is a straight line. The phase shift between signals is

  4. A.
    zero
    B.
    90°
    C.
    either zero or 180°
    D.
    either 90° or 270°

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  5. The scale of a dynamometer is linear when used as

  6. A.
    ammeter
    B.
    voltmeter
    C.
    wattmeter
    D.
    both (a) and (c)

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  7. Three phase four wire induction energy meter is used to measure

  8. A.
    energy in 3 phase balanced star load
    B.
    energy in 3 phase balanced delta load
    C.
    energy in 3 phase unbalanced load
    D.
    either (a) or (b)

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  9. Thermistors are made of

  10. A.
    pure metals
    B.
    pure insulators
    C.
    tintered mixture of metallic oxides
    D.
    pure semiconductors

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  11. An induction wattmeter can be used for ac only.

  12. A.
    True
    B.
    False

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  13. To measure a resistance of about 8 ohms we should use

  14. A.
    Kelvin's double bridge
    B.
    Wheatstone bridge
    C.
    Meggar
    D.
    Either (b) or (c)

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  15. For measuring temperatures below 800°C with high accuracy, the best instrument is

  16. A.
    optical pyrometer
    B.
    thermistor based thermometer
    C.
    GaAs junction diode thermometer
    D.
    platinum resistance thermometer

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  17. Panel instruments are generally mounted vertically.

  18. A.
    True
    B.
    False

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  19. Assertion (A): Many instruments use eddy current damping.

    Reason (R): Eddy currents set up a magnetic flux which opposes the original movement which generates them.

  20. 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

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