MCQOPTIONS
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MCQOPTIONS
This section includes 53 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following protects a cable against mechanical injury___________? |
| A. | Bedding |
| B. | Sheath |
| C. | Armouring |
| D. | None of the above |
| Answer» D. None of the above | |
| 2. |
Underground cables are laid at sufficient depth___________? |
| A. | to minimise 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 | |
| 3. |
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 | |
| 4. |
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» B. 0.2 to 0.4 mm | |
| 5. |
The surge resistance of cable is__________? |
| A. | 5 ohms |
| B. | 20 ohms |
| C. | 50 ohms |
| D. | 100 ohms |
| Answer» D. 100 ohms | |
| 6. |
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 | |
| 7. |
The minimum dielectric stress in a cable is at_____________? |
| A. | armour |
| B. | bedding |
| C. | conductor surface |
| D. | lead sheath |
| Answer» E. | |
| 8. |
The metallic sheath may be made of lead or lead alloy or of aluminium ? |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 9. |
The material for armouring on cable is usually__________? |
| A. | steel tape |
| B. | galvanised steel wire |
| C. | any of the above |
| D. | none of the above |
| Answer» D. none of the above | |
| 10. |
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 |
| Answer» D. none of the above | |
| 11. |
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 | |
| 12. |
The insulating material should have____________? |
| A. | low permittivity |
| B. | high resistivity |
| C. | high dielectric strength |
| D. | all of the above |
| Answer» E. | |
| 13. |
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. | |
| 14. |
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. | |
| 15. |
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 |
| E. | none of the above |
| Answer» D. zero at the conductor as well as on the sheath | |
| 16. |
The disadvantage with paper as insulating material is____________? |
| A. | it is hygroscopic |
| B. | it has high capacitance |
| C. | it is an organic material |
| D. | none of the above |
| Answer» B. it has high capacitance | |
| 17. |
The current carrying capacity of cables in D.C. is more than that in A.C. mainly due to__________? |
| A. | absence of harmonics |
| B. | non-existence of any stability limit |
| C. | smaller dielectric loss |
| D. | absence of ripples |
| E. | none of the above |
| Answer» D. absence of ripples | |
| 18. |
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. | |
| 19. |
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 |
| Answer» D. none of the above | |
| 20. |
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 | |
| 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 |
| Answer» E. | |
| 22. |
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 | |
| 23. |
Rubber is most commonly used insulation in cables |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 24. |
PVC stands for____________? |
| A. | polyvinyl chloride |
| B. | post varnish conductor |
| C. | pressed and varnished cloth |
| D. | positive voltage conductor |
| E. | none of the above |
| Answer» B. post varnish conductor | |
| 25. |
Pressure cables are generally not used beyond__________? |
| A. | 11 kV |
| B. | 33 kV |
| C. | 66 kV |
| D. | 132 kV |
| Answer» D. 132 kV | |
| 26. |
Polyethylene has very poor dielectric and ageing properties |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 27. |
Natural rubber is obtained from milky sap of tropical trees |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 28. |
Low tension cables are generally used up to___________? |
| A. | 200 V |
| B. | 500 V |
| C. | 700 V |
| D. | 1000 V |
| Answer» E. | |
| 29. |
It is difficult to maintain oil filled cables____________? |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 30. |
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 | |
| 31. |
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 | |
| 32. |
In the cables, sheaths are used to___________? |
| A. | prevent the moisture from entering the cable |
| B. | provide enough strength |
| C. | provide proper insulation |
| D. | none of the above |
| Answer» B. provide enough strength | |
| 33. |
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 | |
| 34. |
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 | |
| 35. |
In case of three core flexible cable the colour of the neutral is_________? |
| A. | blue |
| B. | black |
| C. | brown |
| D. | none of the above |
| Answer» B. black | |
| 36. |
In capacitance grading of cables we use a _______ dielectric? |
| A. | composite |
| B. | porous |
| C. | homogeneous |
| D. | hygroscopic |
| Answer» B. porous | |
| 37. |
In capacitance grading a homogeneous dielectric is used |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 38. |
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° |
| Answer» C. lags the voltage by 180° | |
| 39. |
In a cable the voltage stress is maximum at____________? |
| A. | sheath |
| B. | insulator |
| C. | surface of the conductor |
| D. | core of the conductor |
| Answer» E. | |
| 40. |
In a cable, the maximum stress under operating conditions is at___________? |
| A. | insulation layer |
| B. | sheath |
| C. | armour |
| D. | conductor surface |
| Answer» E. | |
| 41. |
In a cable immediately above metallic sheath ______ is provided |
| A. | earthing connection |
| B. | bedding |
| C. | armouring |
| D. | none of the above |
| Answer» C. armouring | |
| 42. |
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 | |
| 43. |
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 | |
| 44. |
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 | |
| 45. |
High tension cables are generally used up to_____________? |
| A. | 11kV |
| B. | 33kV |
| C. | 66 kV |
| D. | 132 kV |
| Answer» B. 33kV | |
| 46. |
Empire tape is__________? |
| A. | varnished cambric |
| B. | vulcanised rubber |
| C. | impregnated paper |
| D. | none of the above |
| Answer» B. vulcanised rubber | |
| 47. |
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 | |
| 48. |
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 | |
| 49. |
Conduit pipes are normally used to protect _______ cables |
| A. | unsheathed cables |
| B. | armoured |
| C. | PVC sheathed cables |
| D. | all of the above |
| Answer» B. armoured | |
| 50. |
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 |
| E. | none of the above |
| Answer» B. grading according to capacitance of cables per km length | |