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EEE :: Electrical Machine Design

  1. The length cf air gap to be provided in ______ is primarily determined by power factor consideration.

  2. A.

     d.c. series motor

    B.

     d.c. shunt motor

    C.

     induction motor

    D.

     synchronous motor


  3. Most common form of A.C. meters met with in every day domestic and industrial installations are

  4. A.

     mercury motor meters

    B.

     commutator motor meters

    C.

     induction type single phase energy meters

    D.

     all of the above


  5. Hot rolled sheets have ______ value of permeability

  6. A.

     zero

    B.

     low

    C.

     high

    D.

     none of the above


  7. An ammeter is a

  8. A.

     secondary instrument

    B.

     absolute instrument

    C.

     recording instrument

    D.

     integrating instrument


  9. An ohmmeter is a

  10. A.

     moving iron instrument

    B.

     moving coil instrument

    C.

     dynamometer instrument

    D.

     none of the above


  11. In a Weston synchronoscope, the fixed coils are connected across

  12. A.

     bus-bars

    B.

     incoming alternator

    C.

     a lamp

    D.

     none of the above


  13. The time taken by the machine to attain 0.632 of its final steady temperature rise is called

  14. A.

     heating time constant

    B.

     cooling time constant

    C.

     either (A) or (B)

    D.

     none of the above


  15. With direct water cooling it is possible to have ratings of about

  16. A.

     200 MW

    B.

     300 MW

    C.

     400 MW

    D.

     600 MW


  17. In induction motors, the length of air gap in kept as small as mechanically possible is order to have

  18. A.

     low power factor

    B.

     high power factor

    C.

     high over load capacity

    D.

     any of the above


  19. Which of the following methods does not take into account the maximum temperature rise under variable loadconditions ?

  20. A.

     Equivalent power method

    B.

     Equivalent current method

    C.

     Method of average losses

    D.

     Equivalent torque method