The skin effect of a conductor will reduce as the__________?

Related Mcqs:

1. Owing to skin effect:

   A. current flows through the half cross-section of the conductor
   B. portion of the conductor near the surface carries more current and core of the conductor carries less current
   C. portion of the conductor near the surface carries less current and core of the conductor carries more cur¬rent
   D. any of the above
   E. none of the above

2. On which of the following factors skin effect depends?

   A. Frequency of the current
   B. Size of the conductor
   C. Resistivity of the conductor material
   D. All of the above

3. A conductor, due to sag between two supports, takes the form of____________?

   A. semi-circle
   B. triangle
   C. ellipse
   D. catenary

4. jCorona usually occurs when the electrostatic stress in air around the conductor exceeds?

   A. 6.6 kV (r.m.s. value)/cm
   B. 11 kV (r.m.s. value)/cm
   C. 22 kV (maximum value)/cm
   D. 30 kV (maximum value)/cm

5. When a conductor carries more current on the surface as compared to core, it is due to___________?

   A. permeability variation
   B. corona
   C. skin effect
   D. unsymmetrical fault
   E. none of the above

6. When a live conductor of public electric supply breaks down and touches the earth which of the following will happen?

   A. Current will flow to earth
   B. Supply voltage will drop
   C. Supply voltage will increase
   D. No current will flow in the conductor
   E. None of the above

7. If variable part of annual cost on account of interest and depreciation on the capital outlay is equal to the annual cost of electrical energy wasted in the conductors, the total annual cost will be minimum and the corresponding size of conductor will be most economical. This statement is known as___________________?

   A. Kelvin’s law
   B. Ohm’s law
   C. Kirchhoffs law
   D. Faraday’s law
   E. none of the above

8. The effect of corona can be detected by___________?

   A. presence of ozone detected by odour
   B. hissing sound
   C. faint luminous glow of bluish colour
   D. all of the above

9. Constant voltage transmission entails the following disadvantage?

   A. large conductor area is required for same power transmission
   B. short-circuit current of the system is increased
   C. either of the above
   D. none of the above

10. Transmitted power remaining the same, if supply voltage of a D.C. 2-wire feeder is increased 100 percent, saving in copper is____________________?

    A. 25 percent
    B. 50 percent
    C. 75 percent
    D. 100 percent