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ECE :: Measurements and Instrumentation

  1. Assertion (A): The sign and magnitude of displacement can be measured by an LVDT.

    Reason (R): LVDT is based on the principle of mutual inductance.

  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

  3. In Maxwell's bridge the unknown inductance is measured by comparing it with a standard capacitor.

  4. A.
    True
    B.
    False

  5. Magnetic deflection sensitivity is defined as

  6. A.
    deflection/flux density
    B.
    (deflection/flux density)0.5
    C.
    (Deflection)0.5/flux density
    D.
    none of the above

  7. Which of the following is active transducer?

  8. A.
    Photoelectric
    B.
    Photovoltaic
    C.
    Photoconductive
    D.
    Photoemissive

  9. Which is the displacement transducer with excellent sensitivity, linearity and resolution?

  10. A.
    Incremental encoder
    B.
    Absolute encoder
    C.
    LVDT
    D.
    Strain gauge

  11. The accuracy of a multimeter is about

  12. A.
    ± 0.5%
    B.
    ± 3%
    C.
    ± 0.01%
    D.
    ± 10%

  13. Induction wattmeter is an absolute instrument.

  14. A.
    True
    B.
    False

  15. In a current transformers

  16. A.
    the number of turns in primary and secondary windings are nearly equal
    B.
    the number of primary turns is very small as compared to number of secondary turns.
    C.
    the number of secondary turns is very small as compared to the number of primary turns
    D.
    either (a) or (c).

  17. The time base of a high frequency CRO whose screen diameter is 10 cm is set at 10 μ sec/cm. The lowest frequency which can be fully displayed on the screen is

  18. A.
    more than 100 kHz
    B.
    equal to 100 kHz
    C.
    equal to 10 kHz
    D.
    less than 10 kHz

  19. Eddy currents are essential for the deflecting torque of an induction wattmeter.

  20. A.
    True
    B.
    False