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

Question: The advantage of oil filled cables is_________?

• 1. more perfect impregnation
• 2. smaller overall size
• 3. no ionisation, oxidation and formation of voids
• 4. all of the above

Question: The breakdown voltage of a cable depends on_____________?

• 1. presence of moisture
• 2. working temperature
• 3. time of application of the voltage
• 4. all of the above

Question: The thickness of metallic shielding on cables is usually_______________?

• 1. 0.04 mm
• 2. 0.2 to 0.4 mm
• 3. 3 to 5 mm
• 4. 40 to 60 mm

Question: Underground cables are laid at sufficient depth___________?

• 1. to minimise temperature stresses
• 2. to avoid being unearthed easily due to removal of soil
• 3. to minimize the effect of shocks and vibrations due to gassing vehicles, etc
• 4. for all of the above reasons

Question: The electrostatic stress in underground cables is_________?

• 1. same at the conductor and the sheath
• 2. minimum at the conductor and maximum at the sheath
• 3. maximum at the conductor and minimum at the sheath
• 4. zero at the conductor as well as on the sheath