In capacitance grading of cables we use a _______ dielectric?

Related Mcqs:

1. In capacitance grading a homogeneous dielectric is used

   A. Yes
   B. No

2. Capacitance grading of cable implies__________?

   A. use of dielectrics of different permeabilities
   B. grading according to capacitance of cables per km length
   C. cables using single dielectric in different concentrations
   D. capacitance required to be introduced at different lengths to counter the effect of inductance
   E. none of the above

3. Conduit pipes are normally used to protect _______ cables

   A. unsheathed cables
   B. armoured
   C. PVC sheathed cables
   D. all of the above

4. Dielectric strength of rubber is around____________?

   A. 5 kV/mm
   B. 15 kV/mm
   C. 30 kV/mm
   D. 200 kV/mm

5. The minimum dielectric stress in a cable is at_____________?

   A. armour
   B. bedding
   C. conductor surface
   D. lead sheath

6. If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be_______________?

   A. 5 kV/mm
   B. 10 kV/mm
   A. 15 kV/mm
   D. 30 kV/mm

7. Polyethylene has very poor dielectric and ageing properties

   A. Yes
   B. No

8. A certain cable has an insulation of relative permittivity 4. If the insulation is replaced by one of relative permittivity 2, the capacitance of the cable will become_____________?

   A. one half
   B. double
   C. four times
   D. none of the above

9. Cables for 220 kV lines are invariably____________?

   A. mica insulated
   B. paper insulated
   C. compressed oil or compressed gas insulated
   D. rubber insulated
   E. none of the above

10. The electrostatic stress in underground cables is_________?

    A. same at the conductor and the sheath
    B. minimum at the conductor and maximum at the sheath
    C. maximum at the conductor and minimum at the sheath
    D. zero at the conductor as well as on the sheath
    E. none of the above