ELECTRICIAN 2nd YEAR MODULE – Transmission and Distribution ONLINE TEST

Question 1 of 25

1. 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 1 of 25

Question 2 of 25

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

Not liable to the hazards from lightning discharges

Public safety is more

Faults can be located easily

No interference with the communication lines

Question 2 of 25

Question 3 of 25

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

To reduce the line voltage drop

To minimize the line sag

To increase the tensile strength

To increase the current carrying capacity

Question 3 of 25

Question 4 of 25

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

Two phase four wire

Two phase three wire

Three phase three wire

Single phase two wire

Question 4 of 25

Question 5 of 25

5. What is the name of line insulator?

Pin type insulator

Shackle type insulator

Disc type insulator

Suspension type insulator

Question 5 of 25

Question 6 of 25

6. What is ACSR stands for?

Aluminium Conductor Steel Reinforced

Aluminium Core Steel Reinforced

Aluminium Covered Steel Reinforced

All Conductors Steel Reinforced

Question 6 of 25

Question 7 of 25

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

Straight joint through connectors

Straight sleeve joint

Compression joint for ACSR

Twisted joint

Question 7 of 25

Question 8 of 25

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

No effect, remain same

Becomes negligible

Increases to maximum

Decreases half of the value

Question 8 of 25

Question 9 of 25

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

Distribution substation

Mobile substation

Mining substation

Secondary substation

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 one Mega ohm

Infinity

More than two Mega ohms

More than three Mega ohms

Question 10 of 25

Question 11 of 25

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

Hard drawn copper

ACSR

Galvanised iron

Aluminium

Question 11 of 25

Question 12 of 25

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

Avoid sparking

Avoid atmospheric pressure

Avoid corrosion

Avoid oxide formation

Question 12 of 25

Question 13 of 25

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

Holding the insulators where the conductors are fastened

Reduce the sag of the lines between poles

Provide more support to the O.H pole

Protect from short between conductors

Question 13 of 25

Question 14 of 25

14. What is the name of the insulator?

Stay insulator

Shackle insulator

Single shed pin insulator

Suspension insulator

Question 14 of 25

Question 15 of 25

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

Shackle insulator

Suspension insulator

Pin insulator

Strain insulator

Question 15 of 25

Question 16 of 25

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

1200 W

3000 W

800 W

2400 W

Question 16 of 25

Question 17 of 25

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

Service mains

Feeders

Distributors

Service lines

Question 17 of 25

Question 18 of 25

18. 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 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?

Only the damaged disc will not function

Damaged insulator and the adjacent insulator will not function

No effect operates normally

Whole string become useless

Question 19 of 25

Question 20 of 25

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

Disables continuous water flow in rainy season

Not to attract birds to sit on it

To withstand high voltage

To offer high mechanical strength

Question 20 of 25

Question 21 of 25

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

Avoids short circuit between conductors

Holding the insulators on overhead line

Supporting the line conductors

Reduces conductor sag between supports

Question 21 of 25

Question 22 of 25

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

Post insulator

Disc insulator

Stay insulator

Pin insulator

Question 22 of 25

Question 23 of 25

23. 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 heat loss

No corona loss

No skin effect

Question 23 of 25

Question 24 of 25

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

Post insulator

Strain insulator

Shackle insulator

Pin insulator

Question 24 of 25

Question 25 of 25

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

Keeping binding turns very close

Providing more than one binding

Providing guard wires below the conductors

Making binding turns very tight

Question 25 of 25