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ECE :: Measurements and Instrumentation

  1. A 1 mA meter is to be converted to 1 A ammeter. The meter resistance is 100 Ω. The value of shunt resistance is

  2. A.
    0.001 Ω
    B.
    0.1001 Ω
    C.
    100 Ω
    D.
    1000 Ω

  3. The use of thermocouple meters for ac measurement leads to a scale which is

  4. A.
    linear
    B.
    square law
    C.
    logarithmic
    D.
    exponential

  5. Assertion (A): A low power factor wattmeter has special constructional features to ensure accurate measurement.

    Reason (R): Extension of wattmeter range in dc circuit can be easily done by using current and potential transformer.

  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 dynamometer wattmeter is non linear.

  8. A.
    True
    B.
    False

  9. Magnetic deflection is inversely proportional to

  10. A.
    voltage
    B.
    (voltage)0.5
    C.
    (voltage)1.5
    D.
    (voltage)2

  11. The most commonly used moving iron instruments are

  12. A.
    repulsion type
    B.
    attraction type
    C.
    a combination of attraction and repulsion type
    D.
    none of the above

  13. A moving iron instrument can be used for

  14. A.
    dc only
    B.
    ac only
    C.
    both dc and ac
    D.
    dc and high frequency ac

  15. Two voltmeters are each 0-300 V range. Their internal resistances are 10 kΩ and 20 kΩ They are connected is series and a voltage of 400 V is applied. Their readings respectively will be

  16. A.
    266.6 and 133.3 V
    B.
    133.3 and 266.6 V
    C.
    200 V each
    D.
    100 and 300 V

  17. A 300 V voltmeter has an accuracy of ± 2% of full scale deflection. When the reading is 222 V, the actual voltage

  18. A.
    lies between 217.56 and 226.44 V
    B.
    lies between 217.4 and 226.6 V
    C.
    lies between 216 and 228 V
    D.
    is exact 222 V

  19. In a thermocouple two metal junctions between metals M1 and M2 are kept at temperature T1 and T2. The thermocouple emf is produced because

  20. A.
    M1, M2 are similar and T1, T2 are equal
    B.
    M1, M2 are similar but T1, T2 are unequal
    C.
    M1, M2 are dissimilar but T1, T2 are equal
    D.
    M1, M2 are dissimilar but T1, T2 are unequal