In congested areas where excavation is expensive and inconvenient ‘draw in system’ of laying of underground cables is often adopted
A. Yes
B. No
Cables
It is difficult to maintain oil filled cables____________?
It is difficult to maintain oil filled cables____________?
A. Yes
B. No
The metallic sheath may be made of lead or lead alloy or of aluminium ?
The metallic sheath may be made of lead or lead alloy or of aluminium ?
A. Yes
B. No
If the length of a cable is doubled, its capacitance____________?
If the length of a cable is doubled, its capacitance____________?
A. becomes one-fourth
B. becomes one-half
C. becomes double
D. remains unchanged
In the cables, sheaths are used to___________?
In the cables, sheaths are used to___________?
A. prevent the moisture from entering the cable
B. provide enough strength
E. provide proper insulation
D. none of the above
The breakdown of insulation of the cable can be avoided economically by the use of___________?
The breakdown of insulation of the cable can be avoided economically by the use of___________?
A. inter-sheaths
B. insulating materials with different dielectric constants
C. both (A) and (B)
D. none of the above
The intersheaths in the cables are used to_____________?
The intersheaths in the cables are used to_____________?
A. minimize the stress
B. avoid the requirement of good insulation
C. provide proper stress distribution
D. none of the above
If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be_______________?
If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be_______________?
A. 5 kV/mm
B. 10 kV/mm
A. 15 kV/mm
D. 30 kV/mm
In cables the charging current__________?
In cables the charging current__________?
A. lags the voltage by 90°
B. leads the voltage by 90°
C. lags the voltage by 180°
D. leads the voltage by 180°
Solid type cables are considered unreliable beyond 66 kV because___________?
Solid type cables are considered unreliable beyond 66 kV because___________?
A. insulation may melt due to higher temperature
B. skin effect dominates on the conductor
C. of corona loss between conductor and sheath material
D. there is a danger of breakdown of insulation due to the presence of voids