Q.1
In a cable the voltage stress is maximum at
  • sheath
  • insulator
  • surface of the conductor
  • core of the conductor
Q.2
A cable carrying alternating current has
  • hysteresis losses only
  • hysteresis and leakage losses only
  • hysteresis, leakage and copper losses only
  • hysteresis, leakage, copper and friction losses
Q.3
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
Q.4
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
Q.5
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
Q.6
If the length of a cable is doubled, its capacitance
  • becomes one-fourth
  • becomes one-half
  • becomes double
  • remains unchanged
Q.7
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
Q.8
In case of three core flexible cable the colour of the neutral is
  • blue
  • black
  • brown
  • none of the above
Q.9
Cables are used forkV lines.
  • High tension
  • Super tension
  • Extra high tension
  • Extra super voltage
Q.10
Conduit pipes are normally used to protect _____ cables.
  • unsheathed cables
  • armoured
  • PVC sheathed cables
  • all of the above
Q.11
In single core cables armouring is not done to
  • avoid excessive sheath losses
  • make it flexible
  • either of the above
  • none of the above
Q.12
Dielectric strength of rubber is around
  • 5 kV/mm
  • 15 kV/mm
  • 30 kV/mm
  • 200 kV/mm
Q.13
Low tension cables are generally used upto
  • 200 V
  • 500 V
  • 700 V
  • 1000 V
Q.14
In a cable, the maximum stress under operating conditions is at
  • insulation layer
  • sheath
  • armour
  • conductor surface
Q.15
High tension cables are generally used upto
  • 11kV
  • 33kV
  • 66 kV
  • 132 kV
Q.16
High tension cables are generally used upto
  • 11kV
  • 33kV
  • 66 kV
  • 132 kV
Q.17
The surge resistance of cable is
  • 5 ohms
  • 20 ohms
  • 50 ohms
  • 100 ohms
Q.18
The surge resistance of cable is
  • 5 ohms
  • 20 ohms
  • 50 ohms
  • 100 ohms
Q.19
In the cables, sheaths are used to
  • prevent the moisture from entering the cable
  • provide enough strength
  • provide proper insulation
  • none of the above
Q.20
A certain cable has an insulation of relative permittivityIf the insulation is replaced by one of relative permittivitythe capacitance of the cable will become
  • one half
  • double
  • four times
  • none of the above
Q.21
If a cable of homogeneous insulation has a maximum stress ofkV/mm, then thedielectric strength of insulation should be
  • 5 kV/mm
  • 10 kV/mm
  • 15 kV/mm
  • 30 kV/mm
Q.22
In the cables, sheaths are used to
  • prevent the moisture from entering the cable
  • provide enough strength
  • provide proper insulation
  • none of the above
Q.23
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°
Q.24
The intersheaths in the cables are used to
  • minimize the stress
  • avoid the requirement of good insulation
  • provide proper stress distribution
  • none of the above
Q.25
The intersheaths in the cables are used to
  • minimize the stress
  • avoid the requirement of good insulation
  • provide proper stress distribution
  • none of the above
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