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ECE :: Measurements and Instrumentation

  1. One single phase wattmeter operating on 230V and 5A for 5 hours makes 1940 revolutions. Meter constant in revolutions is 400. What is the power factor of the land?

  2. A.

     1

    B.

     0.84

    C.

     0.73

    D.

     0.65


  3. The spring material used in a spring control device should have the following property.

  4. A.

     Should be nonmagnetic

    B.

     Most be of low temperature coefficient

    C.

     Should have low specific resistance

    D.

     All of the above


  5. Why is a MISC meter not recommended for DC measurement?

  6. A.

     The meter is calibrated for AC and it’s error for DC would be high

    B.

     The meter does not respond to DC signals

    C.

     The error is high due to hysteresis effect

    D.

     The error is high due to eddy current effect


  7. A moving iron ammeter may be compensated for frequency errors by

  8. A.

     A shunt resistance

    B.

     A series inductance

    C.

     Shunt capacitance

    D.

     Series resistance


  9. Which of the following meters has a linear scale?

  10. A.

     Thermocouple meter

    B.

     Moving iron meter

    C.

     Hot wore meter

    D.

     Moving coil meter


  11. For handling greater currents induction watt-meters are used in conjunction with

  12. A.

     Potential transformers

    B.

     Current transformers

    C.

     Power transformers

    D.

     Either of the above


  13. When using ohmmeter, applied voltage is to be disconnected from the circuit because

  14. A.

     Voltage source will increase resistance

    B.

     Current will decrease resistance

    C.

     The ohmmeter has its own internal battery

    D.

     None of the above


  15. A 10MHz CRO has

  16. A.

     5MHz sweep

    B.

     10MHz vertical oscillator

    C.

     10MHz horizontal oscillator

    D.

     10MHz supply frequency


  17. A CRO can display

  18. A.

     AC signals

    B.

     DC signals

    C.

     Both AC and DC signals

    D.

     Time invariant signals


  19. A galvanometer has

  20. A.

     Air friction damping

    B.

     Fluid friction damping

    C.

     Spring coil damping

    D.

     Eddy current damping