MCQOPTIONS
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MCQOPTIONS
This section includes 121 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Dielectric strength of rubber is around |
| A. | 5 kV/mm |
| B. | 15 kV/mm |
| C. | 30 kV/mm |
| D. | 200 kV/mm |
| Answer» D. 200 kV/mm | |
| 52. |
In capacitance grading a homogeneous dielectric is used. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 53. |
Underground cables are laid at sufficient depth |
| A. | To minimize temperature stresses |
| B. | To avoid being unearthed easily due to removal of soil |
| C. | To minimize the effect of shocks and vibrations due to gassing vehicles, etc. |
| D. | For all of the above reasons |
| Answer» D. For all of the above reasons | |
| 54. |
The insulating material for a cable should have |
| A. | Low cost |
| B. | High dielectric strength |
| C. | High mechanical strength |
| D. | All of the above |
| Answer» E. | |
| 55. |
The bedding on a cable consists of |
| A. | Hessian cloth |
| B. | Jute |
| C. | Any of the above |
| D. | None of the above |
| Answer» D. None of the above | |
| 56. |
In single core cables armouring is not done to~! |
| A. | Avoid excessive sheath losses |
| B. | Make it flexible |
| C. | Either of the above |
| D. | None of the above |
| Answer» B. Make it flexible | |
| 57. |
In the cables, the location of fault is usually found out by comparing~! |
| A. | The resistance of the conductor |
| B. | The inductance of conductors |
| C. | The capacitances of insulated conductors |
| D. | All above parameters |
| Answer» D. All above parameters | |
| 58. |
Polyethylene has very poor dielectric and ageing properties.%! |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 59. |
The insulating material should have%! |
| A. | Low permittivity |
| B. | High resistivity |
| C. | High dielectric strength |
| D. | All of the above |
| Answer» E. | |
| 60. |
High tension cables are generally used up to%! |
| A. | 11 kV |
| B. | 33 kV |
| C. | 66 kV |
| D. | 132 kV |
| Answer» B. 33 kV | |
| 61. |
In case of three core flexible cable the color of the neutral is%! |
| A. | Blue |
| B. | Black |
| C. | Brown |
| D. | None of the above |
| Answer» B. Black | |
| 62. |
The surge resistance of cable is%! |
| A. | 5 ohms |
| B. | 20 ohms |
| C. | 50 ohms |
| D. | 100 ohms |
| Answer» D. 100 ohms | |
| 63. |
Dielectric strength of rubber is around%! |
| A. | 5 kV/mm |
| B. | 15 kV/mm |
| C. | 30 kV/mm |
| D. | 200 kV/mm |
| Answer» D. 200 kV/mm | |
| 64. |
The thickness of the layer of insulation on the conductor, in cables, depends upon%! |
| A. | Reactive power |
| B. | Power factor |
| C. | Voltage |
| D. | Current carrying capacity |
| Answer» D. Current carrying capacity | |
| 65. |
The metallic sheath may be made of lead or lead alloy or of aluminum.%! |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 66. |
The breakdown voltage of a cable depends on%! |
| A. | Presence of moisture |
| B. | Working temperature |
| C. | Time of application of the voltage |
| D. | All of the above |
| Answer» E. | |
| 67. |
Copper as conductor for cables is used as%! |
| A. | Annealed |
| B. | Hardened and tempered |
| C. | Hard drawn |
| D. | Alloy with chromium |
| Answer» B. Hardened and tempered | |
| 68. |
Cables, generally used beyond 66 kV are%! |
| A. | Oil filled |
| B. | S.L. type |
| C. | Belted |
| D. | Armoured |
| Answer» B. S.L. type | |
| 69. |
In capacitance grading a homogeneous dielectric is used.%! |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 70. |
The insulation of the cable decreases with%! |
| A. | The increase in length of the insulation |
| B. | The decrease in the length of the insulation |
| C. | Either (A) or (B) |
| D. | None of the above |
| Answer» B. The decrease in the length of the insulation | |
| 71. |
Cables for 220 kV lines are invariably%! |
| A. | Mica insulated |
| B. | Paper insulated |
| C. | Compressed oil or compressed gas insulated |
| D. | Rubber insulated |
| Answer» D. Rubber insulated | |
| 72. |
The minimum dielectric stress in a cable is at%! |
| A. | Armour |
| B. | Bedding |
| C. | Conductor surface |
| D. | Lead sheath |
| Answer» E. | |
| 73. |
The thickness of metallic shielding on cables is usually%! |
| A. | 0.04 mm |
| B. | 0.2 to 0.4 mm |
| C. | 3 to 5 mm |
| D. | 40 to 60 mm |
| Answer» D. 40 to 60 mm | |
| 74. |
The advantage of cables over overhead transmission lines is%! |
| A. | Easy maintenance |
| B. | Low cost |
| C. | Can be used in congested areas |
| D. | Can be used in high voltage circuits |
| Answer» D. Can be used in high voltage circuits | |
| 75. |
Underground cables are laid at sufficient depth%! |
| A. | To minimize temperature stresses |
| B. | To avoid being unearthed easily due to removal of soil |
| C. | To minimize the effect of shocks and vibrations due to gassing vehicles, etc. |
| D. | For all of the above reasons |
| Answer» D. For all of the above reasons | |
| 76. |
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 |
| Answer» E. | |
| 77. |
If the length of a cable is doubled, its capacitance%! |
| A. | Becomes one-fourth |
| B. | Becomes one-half |
| C. | Becomes double |
| D. | Remains unchanged |
| Answer» D. Remains unchanged | |
| 78. |
In congested areas where excavation is expensive and inconvenient 'draw in system' of laying of underground cables is often adopted.%! |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 79. |
The advantage of oil filled cables is%! |
| A. | More perfect impregnation |
| B. | Smaller overall size |
| C. | No ionization, oxidation and formation of voids |
| D. | All of the above |
| Answer» E. | |
| 80. |
PVC stands for%! |
| A. | Polyvinyl chloride |
| B. | Post varnish conductor |
| C. | Pressed and varnished cloth |
| D. | Positive voltage conductor |
| Answer» B. Post varnish conductor | |
| 81. |
The insulating material for a cable should have%! |
| A. | Low cost |
| B. | High dielectric strength |
| C. | High mechanical strength |
| D. | All of the above |
| Answer» E. | |
| 82. |
Pressure cables are generally not used beyond%! |
| A. | 11 kV |
| B. | 33 kV |
| C. | 66 kV |
| D. | 132 kV |
| Answer» D. 132 kV | |
| 83. |
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 |
| C. | 15 kV/mm |
| D. | 30 kV/mm |
| Answer» C. 15 kV/mm | |
| 84. |
A cable carrying alternating current has%! |
| A. | Hysteresis losses only |
| B. | Hysteresis and leakage losses only |
| C. | Hysteresis, leakage and copper losses only |
| D. | Hysteresis, leakage, copper and friction losses |
| Answer» C. Hysteresis, leakage and copper losses only | |
| 85. |
Rubber is most commonly used insulation in cables.%! |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 86. |
Natural rubber is obtained from milky sap of tropical trees.%! |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 87. |
The bedding on a cable consists of%! |
| A. | Hessian cloth |
| B. | Jute |
| C. | Any of the above |
| D. | None of the above |
| Answer» D. None of the above | |
| 88. |
The electrostatic stress in underground cables is%! |
| A. | Same at the conductor and the sheath |
| B. | Minimum at the conductor and maximum at the sheath |
| C. | Maximum at the conductor and minimum at the sheath |
| D. | Zero at the conductor as well as on the sheath |
| Answer» D. Zero at the conductor as well as on the sheath | |
| 89. |
Is a cable is to be designed for use on 1000 kV, which insulation would you prefer ?%! |
| A. | Polyvinyle chloride |
| B. | Vulcanised rubber |
| C. | Impregnated paper |
| D. | Compressed SFe gas |
| E. | none of the above |
| Answer» E. none of the above | |
| 90. |
It is difficult to maintain oil filled cables.%! |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 91. |
Which of the following insulation is used in cables?%! |
| A. | Varnished cambric |
| B. | Rubber |
| C. | Paper |
| D. | Any of the above |
| Answer» E. | |
| 92. |
The current carrying capacity of cables in D.C. is more than that in A.C. mainly due to%! |
| A. | Absence of harmonics |
| B. | Nonexistence of any stability limit |
| C. | Smaller dielectric loss |
| D. | Absence of ripples |
| Answer» D. Absence of ripples | |
| 93. |
Capacitance grading of cable implies%! |
| A. | Use of dielectrics of different permeabilities |
| B. | Grading according to capacitance of cables per km length |
| C. | Cables using single dielectric in different concentrations |
| D. | Capacitance required to be introduced at different lengths to counter the effect of inductance |
| Answer» B. Grading according to capacitance of cables per km length | |
| 94. |
If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be%! |
| A. | 2 cm |
| B. | 10 cm |
| C. | 50 cm |
| D. | 400 cm |
| Answer» D. 400 cm | |
| 95. |
The insulating material for cables should%! |
| A. | Be acid proof |
| B. | Be non-inflammable |
| C. | Be non-hygroscopic |
| D. | Have all above properties |
| Answer» E. | |
| 96. |
The relative permittivity of rubber is%! |
| A. | Between 2 and 3 |
| B. | Between 5 and 6 |
| C. | Between 8 and 10 |
| D. | Between 12 and 14 |
| Answer» B. Between 5 and 6 | |
| 97. |
*$_The insulating material for cables should? |
| A. | Be acid proof |
| B. | Be non-inflammable |
| C. | Be non-hygroscopic |
| D. | Have all above properties |
| Answer» E. | |
| 98. |
*$_Capacitance grading of cable implies? |
| A. | Use of dielectrics of different permeabilities |
| B. | Grading according to capacitance of cables per km length |
| C. | Cables using single dielectric in different concentrations |
| D. | Capacitance required to be introduced at different lengths to counter the effect of inductance |
| Answer» B. Grading according to capacitance of cables per km length | |
| 99. |
*$_If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be? |
| A. | 2 cm |
| B. | 10 cm |
| C. | 50 cm |
| D. | 400 cm |
| Answer» D. 400 cm | |
| 100. |
*$_The relative permittivity of rubber is? |
| A. | Between 2 and 3 |
| B. | Between 5 and 6 |
| C. | Between 8 and 10 |
| D. | Between 12 and 14 |
| Answer» B. Between 5 and 6 | |