Dielectric strength of rubber is around____________?

Related Mcqs:

1. 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

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

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

3. In capacitance grading of cables we use a _______ dielectric?

   A. composite
   B. porous
   C. homogeneous
   D. hygroscopic

4. Polyethylene has very poor dielectric and ageing properties

   A. Yes
   B. No

5. In capacitance grading a homogeneous dielectric is used

   A. Yes
   B. No

6. The relative permittivity of rubber is____________?

   A. between 2 and 3
   B. between 5 and 6
   C. between 8 and 10
   D. between 12 and 14

7. Natural rubber is obtained from milky sap of tropical trees

   A. Yes
   B. No

8. Rubber is most commonly used insulation in cables

   A. Yes
   B. No

9. Conduit pipes are normally used to protect _______ cables

   A. unsheathed cables
   B. armoured
   C. PVC sheathed cables
   D. all 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