Question 1 of 25

1. Which electric lines connect the substation to distributors in distribution system?

Service lines

Service mains

Distributors

Feeders

Question 1 of 25

Question 2 of 25

2. What is the name of conductor used on overhead lines?

Aluminium

ACSR

Hard drawn copper

Galvanised iron

Question 2 of 25

Question 3 of 25

3. Which substation the transmission line voltage is stepped down to consumer supply voltage?

Distribution substation

Mobile substation

Secondary substation

Mining substation

Question 3 of 25

Question 4 of 25

4. What is the voltage ratio in A.C distribution line adopted for domestic consumers?

11 KV/415 V

240 V/110 V

415 V/240 V

415 V/110 V

Question 4 of 25

Question 5 of 25

5. What will happen to the string arrangement of disc insulators, if one of the disc insulator gets damaged?

Damaged insulator and the adjacent insulator will not function

No effect operates normally

Whole string become useless

Only the damaged disc will not function

Question 5 of 25

Question 6 of 25

6. What is the name of the insulator?

Suspension insulator

Single shed pin insulator

Stay insulator

Shackle insulator

Question 6 of 25

Question 7 of 25

7. Which type of A.C transmission is universally adopted?

Two phase four wire

Single phase two wire

Two phase three wire

Three phase three wire

Question 7 of 25

Question 8 of 25

8. Which type of line insulator is used for terminating on corner post?

Shackle insulator

Strain insulator

Pin insulator

Suspension insulator

Question 8 of 25

Question 9 of 25

9. What is the reason for the conductor cross-sectional area can fully utilised on transmission of DC as compared to AC?

No skin effect

No power loss

No heat loss

No corona loss

Question 9 of 25

Question 10 of 25

10. What is the advantage of AC power transmission?

Low voltage drop in transmission lines

Corona loss negligible

Voltages can be stepped up and stepped down easily

Stress on transmission lines is minimum

Question 10 of 25

Question 11 of 25

11. What is the purpose of cross-arm in O.H lines?

Provide more support to the O.H pole

Holding the insulators where the conductors are fastened

Reduce the sag of the lines between poles

Protect from short between conductors

Question 11 of 25

Question 12 of 25

12. Which is the permissible load for lighting subcircuit in domestic wiring as per IE rules?

800 W

3000 W

2400 W

1200 W

Question 12 of 25

Question 13 of 25

13. What is the insulation resistance between any two conductors in a medium voltage domestic installation as per IE rules?

More than three Mega ohms

More than two Mega ohms

More than one Mega ohm

Infinity

Question 13 of 25

Question 14 of 25

14. What is the type of over head line joint?

Straight joint through connectors

Twisted joint

Straight sleeve joint

Compression joint for ACSR

Question 14 of 25

Question 15 of 25

15. What is the name of the insulator used in O.H lines?

Post insulator

Shackle insulator

Strain insulator

Pin insulator

Question 15 of 25

Question 16 of 25

16. What is ACSR stands for?

Aluminium Covered Steel Reinforced

All Conductors Steel Reinforced

Aluminium Core Steel Reinforced

Aluminium Conductor Steel Reinforced

Question 16 of 25

Question 17 of 25

17. Which type of line insulator is used at the dead ends of the H.T overhead lines?

Pin insulator

Stay insulator

Post insulator

Disc insulator

Question 17 of 25

Question 18 of 25

18. Why steel is reinforced in ACSR conductors used for over head lines?

To increase the current carrying capacity

To increase the tensile strength

To minimize the line sag

To reduce the line voltage drop

Question 18 of 25

Question 19 of 25

19. What is the main purpose of crossarm used in electric poles?

Holding the insulators on overhead line

Avoids short circuit between conductors

Reduces conductor sag between supports

Supporting the line conductors

Question 19 of 25

Question 20 of 25

20. What is the reason of keeping binding wire gap too close and very tight in pin insulator?

Avoid corrosion

Avoid atmospheric pressure

Avoid oxide formation

Avoid sparking

Question 20 of 25

Question 21 of 25

21. What is the advantage of over head lines compared to underground cable?

Not liable to the hazards from lightning discharges

No interference with the communication lines

Public safety is more

Faults can be located easily

Question 21 of 25

Question 22 of 25

22. What is the name of line insulator?

Disc type insulator

Pin type insulator

Shackle type insulator

Suspension type insulator

Question 22 of 25

Question 23 of 25

23. Why the disc pin insulators outer surface is made by glazing and bent the sides inward?

Disables continuous water flow in rainy season

To offer high mechanical strength

Not to attract birds to sit on it

To withstand high voltage

Question 23 of 25

Question 24 of 25

24. How the sparking on the aluminium cored conductors binding joints can be prevented?

Providing guard wires below the conductors

Keeping binding turns very close

Making binding turns very tight

Providing more than one binding

Question 24 of 25

Question 25 of 25

25. What will happen to the skin effect on the O.H conductors, if the conductor diameter is small (<1cm)?

Decreases half of the value

Increases to maximum

Becomes negligible

No effect, remain same

Question 25 of 25