Electrical Cables MCQ

Test your knowledge with important Electrical Cables MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Electrical Cables MCQs at Bissoy

• In single core cables armouring is not done to
  ক

  Avoid excessive sheath losses

  খ

  Make it flexible

  গ

  Either of the above

  ঘ

  None of the above
• In the cables, the location of fault is usually found out by comparing
  ক

  The resistance of the conductor

  খ

  The inductance of conductors

  গ

  The capacitances of insulated conductors

  ঘ

  All above parameters
• The relative permittivity of rubber is
  ক

  Between 2 and 3

  খ

  Between 5 and 6

  গ

  Between 8 and 10

  ঘ

  Between 12 and 14
• In cables the charging current
  ক

  Lags the voltage by 90°

  খ

  Leads the voltage by 90°

  গ

  Lags the voltage by 180°

  ঘ

  Leads the voltage by 180°
• Which of the following protects a cable against mechanical injury?
  ক

  Bedding

  খ

  Sheath

  গ

  Armouring

  ঘ

  None of the above
• The disadvantage with paper as insulating material is
  ক

  It is hygroscopic

  খ

  It has high capacitance

  গ

  It is an organic material

  ঘ

  None of the above
• In a cable the voltage stress is maximum at
  ক

  Sheath

  খ

  Insulator

  গ

  Surface of the conductor

  ঘ

  Core of the conductor
• The surge resistance of cable is
  ক

  5 ohms

  খ

  20 ohms

  গ

  50 ohms

  ঘ

  100 ohms
• Cables, generally used beyond 66 kV are
  ক

  Oil filled

  খ

  S.L. type

  গ

  Belted

  ঘ

  Armoured
• The advantage of cables over overhead transmission lines is
  ক

  Easy maintenance

  খ

  Low cost

  গ

  Can be used in congested areas

  ঘ

  Can be used in high voltage circuits
• PVC stands for
  ক

  Polyvinyl chloride

  খ

  Post varnish conductor

  গ

  Pressed and varnished cloth

  ঘ

  Positive voltage conductor
• Natural rubber is obtained from milky sap of tropical trees.
  ক

  Yes

  খ

  No
• In case of three core flexible cable the color of the neutral is
  ক

  Blue

  খ

  Black

  গ

  Brown

  ঘ

  None of the above
• Copper as conductor for cables is used as
  ক

  Annealed

  খ

  Hardened and tempered

  গ

  Hard drawn

  ঘ

  Alloy with chromium
• The thickness of metallic shielding on cables is usually
  ক

  0.04 mm

  খ

  0.2 to 0.4 mm

  গ

  3 to 5 mm

  ঘ

  40 to 60 mm
• The advantage of oil filled cables is
  ক

  More perfect impregnation

  খ

  Smaller overall size

  গ

  No ionization, oxidation and formation of voids

  ঘ

  All of the above
• Rubber is most commonly used insulation in cables.
  ক

  Yes

  খ

  No
• The electrostatic stress in underground cables is
  ক

  Same at the conductor and the sheath

  খ

  Minimum at the conductor and maximum at the sheath

  গ

  Maximum at the conductor and minimum at the sheath

  ঘ

  Zero at the conductor as well as on the sheath
• Is a cable is to be designed for use on 1000 kV, which insulation would you prefer ?
  ক

  Polyvinyle chloride

  খ

  Vulcanised rubber

  গ

  Impregnated paper

  ঘ

  Compressed SFe gas

  ঙ

  none of the above
• It is difficult to maintain oil filled cables.
  ক

  Yes

  খ

  No
• Which of the following insulation is used in cables?
  ক

  Varnished cambric

  খ

  Rubber

  গ

  Paper

  ঘ

  Any of the above
• The current carrying capacity of cables in D.C. is more than that in A.C. mainly due to
  ক

  Absence of harmonics

  খ

  Nonexistence of any stability limit

  গ

  Smaller dielectric loss

  ঘ

  Absence of ripples
• The insulating material should have
  ক

  Low permittivity

  খ

  High resistivity

  গ

  High dielectric strength

  ঘ

  All of the above
• The metallic sheath may be made of lead or lead alloy or of aluminum.
  ক

  Yes

  খ

  No
• Cables for 220 kV lines are invariably
  ক

  Mica insulated

  খ

  Paper insulated

  গ

  Compressed oil or compressed gas insulated

  ঘ

  Rubber insulated
• If the length of a cable is doubled, its capacitance
  ক

  Becomes one-fourth

  খ

  Becomes one-half

  গ

  Becomes double

  ঘ

  Remains unchanged
• If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be
  ক

  5 kV/mm

  খ

  10 kV/mm

  গ

  15 kV/mm

  ঘ

  30 kV/mm
• Capacitance grading of cable implies
  ক

  Use of dielectrics of different permeabilities

  খ

  Grading according to capacitance of cables per km length

  গ

  Cables using single dielectric in different concentrations

  ঘ

  Capacitance required to be introduced at different lengths to counter the effect of inductance
• In a cable, the maximum stress under operating conditions is at
  ক

  Insulation layer

  খ

  Sheath

  গ

  Armour

  ঘ

  Conductor surface
• The breakdown of insulation of the cable can be avoided economically by the use of
  ক

  Inter-sheaths

  খ

  Insulating materials with different dielectric constants

  গ

  Both (A) and (B)

  ঘ

  None of the above