Question: The relative permittivity of rubber is____________?

• 1. between 2 and 3
• 2. between 5 and 6
• 3. between 8 and 10
• 4. between 12 and 14

Question: Pressure cables are generally not used beyond__________?

• 1. 11 kV
• 2. 33 kV
• 3. 66 kV
• 4. 132 kV

Question: 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_____________?

• 1. one half
• 2. double
• 3. four times
• 4. none of the above

Question: Solid type cables are considered unreliable beyond 66 kV because___________?

• 1. insulation may melt due to higher temperature
• 2. skin effect dominates on the conductor
• 3. of corona loss between conductor and sheath material
• 4. there is a danger of breakdown of insulation due to the presence of voids

Question: In cables the charging current__________?

• 1. lags the voltage by 90°
• 2. leads the voltage by 90°
• 3. lags the voltage by 180°
• 4. leads the voltage by 180°

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

• 1. 5 kV/mm
• 2. 10 kV/mm
• 3. 15 kV/mm
• 4. 30 kV/mm

Question: The intersheaths in the cables are used to_____________?

• 1. minimize the stress
• 2. avoid the requirement of good insulation
• 3. provide proper stress distribution
• 4. none of the above

Question: The breakdown of insulation of the cable can be avoided economically by the use of___________?

• 1. inter-sheaths
• 2. insulating materials with different dielectric constants
• 3. both (A) and (B)
• 4. none of the above

Question: In the cables, sheaths are used to___________?

• 1. prevent the moisture from entering the cable
• 2. provide enough strength
• 3. provide proper insulation
• 4. none of the above

Question: If the length of a cable is doubled, its capacitance____________?

• 1. becomes one-fourth
• 2. becomes one-half
• 3. becomes double
• 4. remains unchanged