Electrical Cables MCQ Questions and Answers for Practice

1. A cable carrying alternating current has

1. hysteresis losses only
2. hysteresis and leakage losses only
3. hysteresis, leakage and copper losses only
4. hysteresis, leakage, copper and friction losses

2. A certain cable has an insulation of relative permittivity 4. If the insulation is replaced by one of relative permittivity 2, the capacitance of the cable will become

1. one half
2. double
3. four times
4. none of the above

3. Cables are used for 132 kV lines.

1. High tension
2. Super tension
3. Extra high tension
4. Extra super voltage

4. Cables for 220 kV lines are invariably

1. mica insulated
2. paper insulated
3. compressed oil or compressed gas insulated
4. rubber insulated

5. Cables, generally used beyond 66 kV are

1. oil filled
2. S.L. type
3. belted
4. armoured

6. Capacitance grading of cable implies

1. use of dielectrics of different permeabilities
2. grading according to capacitance of cables per km length
3. cables using single dielectric in different concentrations
4. capacitance required to be introduced at different lengths to counter the effect of inductance

7. Conduit pipes are normally used to protect..............cables.

1. unsheathed cables
2. armoured
3. PVC sheathed cables
4. all of the above

8. Copper as conductor for cables is used as

1. annealed
2. hardened and tempered
3. hard drawn
4. alloy with chromium

9. Dielectric strength of rubber is around

1. 5 kV/mm
2. 15 kV/mm
3. 30 kV/mm
4. 200 kV/mm

10. Empire tape is

1. varnished cambric
2. vulcanised rubber
3. impregnated paper
4. none of the above

11. High tension cables are generally used upto

1. 11kV
2. 33kV
3. 66 kV
4. 132 kV

12. If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be

1. 5 kV/mm
2. 10 kV/mm
3. 15 kV/mm
4. 30 kV/mm

13. If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be

1. 2 cm
2. 10 cm
3. 50 cm
4. 400 cm

14. If the length of a cable is doubled, its capacitance

1. becomes one-fourth
2. becomes one-half
3. becomes double
4. remains unchanged

15. In a cable immediately above metallic sheath.............is provided.

1. earthing connection
2. bedding
3. armouring
4. none of the above