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

Question: The disadvantage with paper as insulating material is____________?

• 1. it is hygroscopic
• 2. it has high capacitance
• 3. it is an organic material
• 4. none of the above

Question: The insulating material should have____________?

• 1. low permittivity
• 2. high resistivity
• 3. high dielectric strength
• 4. all of the above

Question: If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be______________?

• 1. 2 cm
• 2. 10 cm
• 3. 50 cm
• 4. 400 cm

Question: Cables for 220 kV lines are invariably____________?

• 1. mica insulated
• 2. paper insulated
• 3. compressed oil or compressed gas insulated
• 4. rubber insulated

Question: Copper as conductor for cables is used as________?

• 1. annealed
• 2. hardened and tempered
• 3. hard drawn
• 4. alloy with chromium