impose limitation on design____________?

Related Mcqs:

1. Electrical machines having power outputs ranging from a few kW up to approximately 250 kW may be classified as_____________?

   A. small size machines
   B. medium size machines
   C. large size machines
   D. any of the above

2. If an insulating material is operated beyond the maximum allowable temperature, its life is_____________?

   A. drastically increased
   B. drastically reduced
   C. unaffected
   D. none of the above

3. The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc?

   A. conduction
   B. convection
   C. radiation
   D. any of the above

4. cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall______________?

   A. Direct
   B. Indirect
   C. Conventional
   D. Any of the above

5. Which of the following methods does not take into account the maximum temperature rise under variable load conditions ?

   A. Equivalent power method
   B. Equivalent current method
   C. Method of average losses
   D. Equivalent torque method

6. Dummy coil should not be used in_________________?

   A. small machines
   B. large machines
   C. either A. or B.
   D. none of the above

7. In transformers using hot rolled steel, the cross-section of the yoke is made about __________ greater than that of the core?

   A. 5 percent
   B. 10 percent
   C. 15 percent
   D. 30 percent
   E. none of the above

8. In a D.C. machine the number of brush arms is _________ the number of poles?

   A. less than
   B. equal to
   C. greater than
   D. none of the above

9. A practical formula for determining the thickness of insulation between low voltage and high voltage windings is__________________?

   A. 1 + 0.2 kVmm
   B. 2 + 0.5 kVmm
   C. 4 + 0.7 kV mm
   D. 5 + 0.9 kV mm

10. The voltage control in electric supply networks in required on account of which of the following reasons ?

    A. Adjustment of voltage at consumers premises within statutory limits
    B. Control of active and reactive power
    C. Adjustment of short period daily and seasonal voltage variations in accordance with variations of load
    D. All of the above