21.
The advantage of oil filled cables is
A
more perfect impregnation
B
smaller overall size
C
no ionisation, oxidation and formation of voids
D
all of the above
Loading practice questions
50 practice sets · Page 2 of 3
The advantage of oil filled cables is
more perfect impregnation
smaller overall size
no ionisation, oxidation and formation of voids
all of the above
The advantage of cables over overhead transmission lines is
easy maintenance
low cost
can be used in congested areas
can be used in high voltage circuits
Solid type cables are considered unreliable beyond 66 kV because
insulation may melt due to higher temperature
skin effect dominates on the conduc¬tor
of corona loss between conductor and sheath material
there is a danger of breakdown of insulation due to the presence of voids
PVC stands for
polyvinyl chloride
post varnish conductor
pressed and varnished cloth
positive voltage conductor
Pressure cables are generally not used beyond
11 kV
33 kV
66 kV
132 kV
Low tension cables are generally used upto
200 V
500 V
700 V
1000 V
Is a cable is to be designed for use on 1000 kV, which insulation would you prefer ?
Polyvinyle chloride
Vulcanised rubber
Impregnated paper
Compressed SFe gas
In the cables, the location of fault is usually found out by comparing
the resistance of the conductor
the inductance of conductors
the capacitances of insulated conductors
all above parameters
In the cables, sheaths are used to
prevent the moisture from entering the cable
provide enough strength
provide proper insulation
none of the above
In single core cables armouring is not done to
avoid excessive sheath losses
make it flexible
either of the above
none of the above
In case of three core flexible cable the colour of the neutral is
blue
black
brown
none of the above
In capacitance grading of cables we use a....................dielectric
composite
porous
homogeneous
hygroscopic
In cables the charging current
lags the voltage by 90°
leads the voltage by 90°
lags the voltage by 180°
leads the voltage by 180°
In a cable, the maximum stress under operating conditions is at
insulation layer
sheath
armour
conductor surface
In a cable the voltage stress is maximum at
sheath
insulator
surface of the conductor
core of the conductor
In a cable immediately above metallic sheath.............is provided.
earthing connection
bedding
armouring
none of the above
If the length of a cable is doubled, its capacitance
becomes one-fourth
becomes one-half
becomes double
remains unchanged
If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be
2 cm
10 cm
50 cm
400 cm
If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be
5 kV/mm
10 kV/mm
15 kV/mm
30 kV/mm
High tension cables are generally used upto
11kV
33kV
66 kV
132 kV