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ECE :: Measurements and Instrumentation

  1. The resistance of voltmeter affects the accuracy of measurement in loss of charge method.

  2. A.
    True
    B.
    False

  3. In a hot wire instrument, the deflection is proportional to

  4. A.
    peak value of ac current
    B.
    average value of ac current
    C.
    rms value of ac current
    D.
    either (a) or (b)

  5. A permanent magnet moving coil meter can be used as

  6. A.
    ac only
    B.
    dc only
    C.
    both ac and dc
    D.
    low frequency ac and dc

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

  8. A.
    half of its initial value
    B.
    twice of its initial value
    C.
    eight times of its initial value
    D.
    one eight of its initial value

  9. Which of the following draws minimum power from source?

  10. A.
    PMMC
    B.
    Electronic voltmeter
    C.
    Electrostatic voltmeter
    D.
    Moving iron voltmeter

  11. A megger has a hand driven dc generator.

  12. A.
    True
    B.
    False

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

  14. A.
    True
    B.
    False

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

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

  16. 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

  17. 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.

  18. 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

  19. Acoustic strain gauges

  20. A.
    have good linearity of measurement
    B.
    do not have long term stability
    C.
    have a large range of measurement
    D.
    have an accuracy range of 0.1-1% depending on environment