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ECE :: Measurements and Instrumentation

  1. Two resistances are R1 = 36 ± 5% and R2 = 75 ± 5%. If they are connected in parallel, the limiting error in percent will be

  2. A.
    5%
    B.
    10%
    C.
    15%
    D.
    20%

  3. For critical damping, the resistance in D'Arsonval galvanometer circuit should be equal to


  4. An ac bridge uses galvanometer as detector.

  5. A.
    True
    B.
    False

  6. In figure, the reading of wattmeter will be proportional

  7. A.
    V I cos θ
    B.
    3 VI cos θ
    C.
    3 VI sin θ
    D.
    V I sin θ

  8. Consider the following statements about mutual inductances:

    1. The value should remain constant under all conditions.
    2. The mutual inductance should not vary with temperature.
    3. The inductance should be independent of excitation.
    4. They have two coils wound on a bobbin of hard magnetic material, coils being separated by a range.
    Out of the above, correct statement are

  9. A.
    2, 3, 4
    B.
    1, 2, 3
    C.
    1, 3, 4
    D.
    1, 2, 4

  10. In low power factor wattmeter, the pressure coil is connected

  11. A.
    to the supply side of current coil
    B.
    to the load side of current coil
    C.
    in either (a) or (b)
    D.
    across the mains

  12. Figure shows the equivalent circuit of resistor. The resistor is non-inductive when

  13. A.
    R = L/C
    B.
    LR = L/C
    C.
    L = CR2
    D.
    C = LR2

  14. The signal to noise ratio in telemetry should be better than

  15. A.
    5 db
    B.
    10 db
    C.
    25 db
    D.
    60 db

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

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

  17. 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

  18. 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

  19. A.
    1 and 2 are corect
    B.
    3 and 4 are correct
    C.
    1 and 3 are correct
    D.
    1, 2, 3, 4 are correct