Question 1 of 25

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

Increases to maximum

Becomes negligible

Decreases half of the value

No effect, remain same

Question 1 of 25

Question 2 of 25

2. What is the advantage of AC power transmission?

Corona loss negligible

Low voltage drop in transmission lines

Stress on transmission lines is minimum

Voltages can be stepped up and stepped down easily

Question 2 of 25

Question 3 of 25

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

Pin insulator

Shackle insulator

Post insulator

Strain insulator

Question 3 of 25

Question 4 of 25

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

Feeders

Service lines

Service mains

Distributors

Question 4 of 25

Question 5 of 25

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

Disables continuous water flow in rainy season

To withstand high voltage

To offer high mechanical strength

Not to attract birds to sit on it

Question 5 of 25

Question 6 of 25

6. What is the name of line insulator?

Suspension type insulator

Pin type insulator

Shackle type insulator

Disc type insulator

Question 6 of 25

Question 7 of 25

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

Disc insulator

Stay insulator

Pin insulator

Post insulator

Question 7 of 25

Question 8 of 25

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

Avoid sparking

Avoid corrosion

Avoid oxide formation

Avoid atmospheric pressure

Question 8 of 25

Question 9 of 25

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

Providing guard wires below the conductors

Providing more than one binding

Keeping binding turns very close

Making binding turns very tight

Question 9 of 25

Question 10 of 25

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

More than two Mega ohms

Infinity

More than three Mega ohms

More than one Mega ohm

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

Mobile substation

Mining substation

Secondary substation

Distribution substation

Question 12 of 25

Question 13 of 25

13. What is the name of the insulator?

Single shed pin insulator

Shackle insulator

Stay insulator

Suspension insulator

Question 13 of 25

Question 14 of 25

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

415 V/110 V

240 V/110 V

11 KV/415 V

415 V/240 V

Question 14 of 25

Question 15 of 25

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

Aluminium

ACSR

Galvanised iron

Hard drawn copper

Question 15 of 25

Question 16 of 25

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

No effect operates normally

Whole string become useless

Only the damaged disc will not function

Damaged insulator and the adjacent insulator will not function

Question 16 of 25

Question 17 of 25

17. What is ACSR stands for?

Aluminium Covered Steel Reinforced

All Conductors Steel Reinforced

Aluminium Conductor Steel Reinforced

Aluminium Core Steel Reinforced

Question 17 of 25

Question 18 of 25

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

Faults can be located easily

Not liable to the hazards from lightning discharges

Public safety is more

No interference with the communication lines

Question 18 of 25

Question 19 of 25

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

Shackle insulator

Strain insulator

Pin insulator

Suspension insulator

Question 19 of 25

Question 20 of 25

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

No power loss

No corona loss

No skin effect

No heat loss

Question 20 of 25

Question 21 of 25

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

To increase the current carrying capacity

To reduce the line voltage drop

To increase the tensile strength

To minimize the line sag

Question 21 of 25

Question 22 of 25

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

Holding the insulators on overhead line

Avoids short circuit between conductors

Supporting the line conductors

Reduces conductor sag between supports

Question 22 of 25

Question 23 of 25

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

1200 W

2400 W

800 W

3000 W

Question 23 of 25

Question 24 of 25

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

Straight sleeve joint

Compression joint for ACSR

Twisted joint

Straight joint through connectors

Question 24 of 25

Question 25 of 25

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

Two phase three wire

Two phase four wire

Three phase three wire

Single phase two wire

Question 25 of 25