Question 1 of 28

1. What type of test is conducted in domestic wiring installation?

 

Insulation resistance test between conductors

Polarity test

Insulation resistance test between conductors and earth

Continuity (or) open circuit test

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Question 2 of 28

2. What causes lamps to glow dim and motors to run slow in domestic wiring?

Open circuit in earth conductor

High value series resistance fault

Short circuit between conductors

Open circuit in neutral line

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Question 3 of 28

3. What is the maximum permissible load for a power sub-circuit as per IE rules?

1500 Watt

2000 Watt

800 Watt

3000 Watt

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Question 4 of 28

4. What test is carried out using a megger?

Insulation resistance test

Polarity test

Earth electrode resistance test

Earth conductor continuity test

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Question 5 of 28

5. What is the advantage of crimping?

Easy replacement

Neat appearance

Reduces load current

Avoids loose connections

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Question 6 of 28

6. For which electrical equipment are 'L' series type MCBs used?

Locomotives

Air conditioners

Geysers

Halogen lamps

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Question 7 of 28

7. Why is system earthing different from equipment earthing?

It protects from all circuit faults

It's associated with current-carrying conductors

It protects humans only

It's connected to non-current-carrying metal parts

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Question 8 of 28

8. Which instrument is used to test new domestic wiring installation?

Multimeter

Shunt-type ohmmeter

Series-type ohmmeter

Megger

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Question 9 of 28

9. Why is AC required to measure earth resistance using an earth resistance tester?

To increase the voltage drop

To decrease the voltage drop

To avoid electrolytic emf interference

To regulate the current

Question 9 of 28

Question 10 of 28

10. What type of test is performed in wiring installation?

Insulation resistance test between conductors and earth

Polarity test

Open circuit test

Insulation resistance test between conductors

Question 10 of 28

Question 11 of 28

11. Why is AC supplied for earth resistance measurement?

Reduce meter current

Provide electrostatic shield

Protect meter coils

Avoid electrolytic emf interference

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Question 12 of 28

12. Why does megger's pointer not stabilize at zero when unused?

No controlling torque

Deflecting torque proportional to current

Air friction damping

Deflecting torque proportional to current²

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Question 13 of 28

13. Where are service connection supply leads connected in a consumer main board?

Main switch

IC cut out

Energy meter

Distribution board

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Question 14 of 28

14. Which earth resistance measurement method is illustrated?

Current dividing

Potential dividing

Fall of current

Fall of potential

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Question 15 of 28

15. Advantage of stranded conductor over solid conductor?

More flexible

Cost is less

More insulation resistance

Less voltage drop

Question 15 of 28

Question 16 of 28

16. What is the minimum size of copper earth continuity conductor used in single-phase domestic wiring as per BIS?

3.5 Sq.mm

3 Sq.mm

1.5 Sq.mm

2.5 Sq.mm

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Question 17 of 28

17. How to control harmonic distortions in neutral connections per IE rules?

Providing plate earthing

Increasing conductor size

Earthing through impedance

Providing parallel earthing

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Question 18 of 28

18. What is the permissible leakage current in domestic wiring installation?

1/500 × Full load current

1/5 × Full load current

1/5000 × Full load current

1/50 × Full load current

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Question 19 of 28

19. What is the megger reading in a dead short wiring installation?

1 MΩ

Infinity

500 MΩ

0 MΩ

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Question 20 of 28

20. What is the function of current reverser in earth resistance testers?

Changes DC supply to AC

Converts AC to DC

Reverses generator rotation direction

Reverses DC polarity

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Question 21 of 28

21. Which principle does the earth resistance tester work on?

Fleming's left hand rule

Mutual induction

Fall of potential method

Self induction

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Question 22 of 28

22. What determines ohmmeter needle deflection in earth testers?

Current in current coil

Current in potential coil

Handle rotation speed

Ratio of currents in two coils

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Question 23 of 28

23. Where is system earthing done?

Domestic wiring installation

Generating station

Small industrial installation

Electroplating installation

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Question 24 of 28

24. How can earth resistance be reduced?

Increasing electrode length

Providing double earthing

Decreasing electrode length

Reducing pit depth

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Question 25 of 28

25. Which method is used to reduce earth resistance value in an existing earth pit?

Increasing the diameter of the earth electrode

Increasing the length of the electrode

Adding more sand and charcoal in earth pits

Keeping wet condition in earth pits always

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Question 26 of 28

26. In which wiring installation is system earthing done?

Domestic wiring

Substations

Commercial wiring

Godown wiring

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Question 27 of 28

27. What happens when a person receives a 20mA shock current?

Painful shock

No sensation

Unconsciousness

Heart convulsions

Question 27 of 28

Question 28 of 28

28. What is the formula to find voltage drop in an AC single-phase wiring circuit?

Voltage drop = IR/2 volt

Voltage drop = I/R volt

Voltage drop = I²R volt

Voltage drop = IR volt

Question 28 of 28