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ECE :: Measurements and Instrumentation

  1. The torque in induction wattmeters due to

  2. A.
    capacitive current
    B.
    electrostatic effect
    C.
    hall effect
    D.
    eddy currents

  3. During testing of an energy meter, the energy recorded by meter was 0.05 kWh and correct energy was found to be 0.09 kWh. The error and correction respectively are

  4. A.
    -0.01 kWh and 0.01 kWh
    B.
    0.01 kWh and -0.01 kWh
    C.
    -0.01 kWh and ± 0.01 kWh
    D.
    ± 0.01 kWh and 0.01 kWh

  5. Two resistances are : R1 = 36 Ω ± 1.89 Ω and R2 = 75 Ω ± 3.75 Ω. The sum R1 + R2 along with limiting error is

  6. A.
    111 Ω ± 1.8 Ω
    B.
    111 Ω ± 3.75 Ω
    C.
    111 Ω ± 5.55 Ω
    D.
    111 Ω ± 1.95 Ω

  7. An instrument of accuracy class 1 can have an error equal to

  8. A.
    + 1% of reading
    B.
    ± 1% of reading
    C.
    ± 1% of full scale deflection
    D.
    + 1% of full scale deflection

  9. In bridge circuit of figure, equivalent resistance between A and B is

  10. A.
    1 Ω
    B.
    0.5 Ω
    C.
    2 Ω
    D.
    1.5 Ω

  11. Assertion (A): The scale a PMMC ammeter is linear.

    Reason (R): The deflecting torque of PMMC is proportional to current in the coil.

  12. 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

  13. Assertion (A): Moving iron instrument can be used on ac or dc.

    Reason (R): In a moving iron instrument deflecting torque is proportional to square of current.

  14. 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

  15. A land line telemetry system is suitable for distance upto

  16. A.
    about 1 km only
    B.
    about 10 km only
    C.
    about 100 km only
    D.
    any of the above

  17. Use of high permeability core in moving iron instrument helps in

  18. A.
    reducing size of meter
    B.
    increasing sensitivity
    C.
    reducing temperature error
    D.
    all of the above

  19. The resistance of series field winding is a low resistance.

  20. A.
    True
    B.
    False