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

Related Mcqs:

1. 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

2. 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

3. The high voltage winding is usually which of the following type ?

   A. Cylindrical winding with circular conductors
   B. Cross-over winding with either circular or small rectangular conductors
   C. Continuous disc type winding with rectangular conductors
   D. All of the above types

4. Multi-layer helical windings are commonly used in the transformers as high voltage windings_______________?

   A. upto 20 kV
   B. upto 50 kV
   C. upto 80 kV
   D. for 110 kV and above

5. Which of the following materials is used in the manufacture of resistance grids to be used in the starters of large motors ?

   A. Copper
   B. Aluminium
   C. Steel
   D. Cast-iron

6. The design of electromagnets is based upon which of the following fundamental equations ?

   A. Force equation
   B. Magnetic circuit equation
   C. Heating equation
   D. Voltage equation
   E. All of the above

7. Which of the following is the commonly used type of electromagnets ?

   A. Flat-faced armature type
   B. Horse shoe type
   C. Flat-faced plunger type
   D. All of the above

8. Which of the following brushes can be used for high values of current density ?

   A. Metal graphite brushes
   B. Hard carbon brushes
   C. Electro-graphitic brushes
   D. Natural graphite brushes

9. For 275 kV transformers, using cold rolled grain oriented steel, which of the following values of flux density may be used?

   A. 1.0 Wb/m2
   B. 1.1 Wb/m2
   C. 1.3 Wb/m2
   D. 1.6 Wb/m2
   E. None of the above

10. Which of the following is the major consideration to evolve a good design?

    A. Cost
    B. Durability
    C. Compliance with performance criteria as laid down in specifications
    D. All of the above

    Submitted by: Abid