Cables
31. The bedding on a cable consists of
- hessian cloth
- jute
- any of the above
- none of the above
Correct answer: (C)
any of the above
32. The breakdown of insulation of the cable can be avoided economically by the use of
- inter-sheaths
- insulating materials with different dielectric constants
- both (a) and (b)
- none of the above
Correct answer: (C)
both (a) and (b)
33. The breakdown voltage of a cable depends on
- presence of moisture
- working temperature
- time of application of the voltage
- all of the above
Correct answer: (D)
all of the above
34. The current carrying capacity of cables in D.C. is more thanthat in A.C. mainly due to
- absence of harmonics
- non-existence of any stability limit
- smaller dielectric loss
- absence of ripples
Correct answer: (C)
smaller dielectric loss
35. The disadvantage with paper as insulating material is
- it is hygroscopic
- it has high capacitance
- it is an organic material
- none of the above
Correct answer: (A)
it is hygroscopic
36. The electrostatic stress in underground cables is
- same at the conductor and the sheath
- minimum at the conductor and maximum at the sheath
- maximum at the conductor and minimum at the sheath
- zero at the conductor as well as on the sheath
Correct answer: (C)
maximum at the conductor and minimum at the sheath
37. The insulating material for a cable should have
- low cost
- high dielectric strength
- high mechanical strength
- all of the above
Correct answer: (D)
all of the above
38. The insulating material for cables should
- be acid proof
- be non-inflammable
- be non-hygroscopic
- have all above properties
Correct answer: (D)
have all above properties
39. The insulating material should have
- low permittivity
- high resistivity
- high dielectric strength
- all of the above
Correct answer: (D)
all of the above
40. The insulation of the cable decreases with
- the increase in length of the insulation
- the decrease in the length of the insulation
- either (a) or (b)
- none of the above
Correct answer: (A)
the increase in length of the insulation