Electrical Cables Multiple Choice Questions and Answers

41. 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

42. The material for armouring on cable is usually

1. steel tape
2. galvanised steel wire
3. any of the above
4. none of the above

43. The minimum dielectric stress in a cable is at

1. armour
2. bedding
3. conductor surface
4. lead sheath

44. 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

45. The surge resistance of cable is

1. 5 ohms
2. 20 ohms
3. 50 ohms
4. 100 ohms

46. 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

47. The thickness of the layer of insulation on the conductor, in cables, depends upon

1. reactive power
2. power factor
3. voltage
4. current carrying capacity

48. 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 minimise the effect of shocks and vibrations due to gassing vehicles, etc.
4. for all of the above reasons

49. Which of the following insulation is used in cables?

1. Varnished cambric
2. Rubber
3. Paper
4. Any of the above

50. Which of the following protects a cable against mechanical injury?

1. Bedding
2. Sheath
3. Armouring
4. None of the above