ELECTRICIAN 2nd YEAR MODULE – Transmission and Distribution ONLINE TEST

Question 1 of 25

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

Disc insulator

Post insulator

Stay insulator

Pin insulator

Question 1 of 25

Question 2 of 25

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

To offer high mechanical strength

Not to attract birds to sit on it

Disables continuous water flow in rainy season

To withstand high voltage

Question 2 of 25

Question 3 of 25

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

Galvanised iron

ACSR

Hard drawn copper

Aluminium

Question 3 of 25

Question 4 of 25

4. What is the advantage of AC power transmission?

Corona loss negligible

Stress on transmission lines is minimum

Voltages can be stepped up and stepped down easily

Low voltage drop in transmission lines

Question 4 of 25

Question 5 of 25

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

To minimize the line sag

To reduce the line voltage drop

To increase the current carrying capacity

To increase the tensile strength

Question 5 of 25

Question 6 of 25

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

415 V/240 V

415 V/110 V

11 KV/415 V

240 V/110 V

Question 6 of 25

Question 7 of 25

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

No interference with the communication lines

Public safety is more

Faults can be located easily

Not liable to the hazards from lightning discharges

Question 7 of 25

Question 8 of 25

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

1200 W

800 W

3000 W

2400 W

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 heat loss

No corona loss

No power loss

Question 9 of 25

Question 10 of 25

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

Service mains

Service lines

Distributors

Feeders

Question 10 of 25

Question 11 of 25

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

Protect from short between conductors

Holding the insulators where the conductors are fastened

Provide more support to the O.H pole

Reduce the sag of the lines between poles

Question 11 of 25

Question 12 of 25

12. What is the name of the insulator?

Shackle insulator

Single shed pin insulator

Stay insulator

Suspension insulator

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?

Infinity

More than two Mega ohms

More than one Mega ohm

More than three Mega ohms

Question 13 of 25

Question 14 of 25

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

Shackle insulator

Strain insulator

Pin insulator

Post insulator

Question 14 of 25

Question 15 of 25

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

Suspension insulator

Shackle insulator

Strain insulator

Pin insulator

Question 15 of 25

Question 16 of 25

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

Keeping binding turns very close

Providing more than one binding

Making binding turns very tight

Providing guard wires below the conductors

Question 16 of 25

Question 17 of 25

17. What is ACSR stands for?

All Conductors Steel Reinforced

Aluminium Covered Steel Reinforced

Aluminium Conductor Steel Reinforced

Aluminium Core Steel Reinforced

Question 17 of 25

Question 18 of 25

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

Single phase two wire

Two phase three wire

Three phase three wire

Two phase four wire

Question 18 of 25

Question 19 of 25

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

Whole string become useless

No effect operates normally

Only the damaged disc will not function

Damaged insulator and the adjacent insulator will not function

Question 19 of 25

Question 20 of 25

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

Avoids short circuit between conductors

Supporting the line conductors

Holding the insulators on overhead line

Reduces conductor sag between supports

Question 20 of 25

Question 21 of 25

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

Twisted joint

Straight sleeve joint

Straight joint through connectors

Compression joint for ACSR

Question 21 of 25

Question 22 of 25

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

Mining substation

Mobile substation

Distribution substation

Secondary substation

Question 22 of 25

Question 23 of 25

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

Decreases half of the value

Becomes negligible

Increases to maximum

No effect, remain same

Question 23 of 25

Question 24 of 25

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

Avoid sparking

Avoid oxide formation

Avoid corrosion

Avoid atmospheric pressure

Question 24 of 25

Question 25 of 25

25. What is the name of line insulator?

Shackle type insulator

Suspension type insulator

Pin type insulator

Disc type insulator

Question 25 of 25