Question 1 of 28

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

Reverses generator rotation direction

Converts AC to DC

Changes DC supply to AC

Reverses DC polarity

Question 1 of 28

Question 2 of 28

2. How can earth resistance be reduced?

Providing double earthing

Decreasing electrode length

Reducing pit depth

Increasing electrode length

Question 2 of 28

Question 3 of 28

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

Painful shock

No sensation

Heart convulsions

Unconsciousness

Question 3 of 28

Question 4 of 28

4. What determines ohmmeter needle deflection in earth testers?

Current in current coil

Handle rotation speed

Ratio of currents in two coils

Current in potential coil

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Question 5 of 28

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

Main switch

Distribution board

IC cut out

Energy meter

Question 5 of 28

Question 6 of 28

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

1500 Watt

2000 Watt

3000 Watt

800 Watt

Question 6 of 28

Question 7 of 28

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

1/5 × Full load current

1/500 × Full load current

1/5000 × Full load current

1/50 × Full load current

Question 7 of 28

Question 8 of 28

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

Locomotives

Air conditioners

Halogen lamps

Geysers

Question 8 of 28

Question 9 of 28

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

To avoid electrolytic emf interference

To decrease the voltage drop

To increase the voltage drop

To regulate the current

Question 9 of 28

Question 10 of 28

10. Where is system earthing done?

Domestic wiring installation

Small industrial installation

Electroplating installation

Generating station

Question 10 of 28

Question 11 of 28

11. What is the advantage of crimping?

Reduces load current

Easy replacement

Neat appearance

Avoids loose connections

Question 11 of 28

Question 12 of 28

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

Voltage drop = IR/2 volt

Voltage drop = IR volt

Voltage drop = I/R volt

Voltage drop = I²R volt

Question 12 of 28

Question 13 of 28

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

Megger

Multimeter

Series-type ohmmeter

Shunt-type ohmmeter

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Question 14 of 28

14. Which earth resistance measurement method is illustrated?

Potential dividing

Fall of current

Current dividing

Fall of potential

Question 14 of 28

Question 15 of 28

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

Adding more sand and charcoal in earth pits

Keeping wet condition in earth pits always

Increasing the diameter of the earth electrode

Increasing the length of the electrode

Question 15 of 28

Question 16 of 28

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

Deflecting torque proportional to current²

Air friction damping

No controlling torque

Deflecting torque proportional to current

Question 16 of 28

Question 17 of 28

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

Open circuit test

Insulation resistance test between conductors

Polarity test

Insulation resistance test between conductors and earth

Question 17 of 28

Question 18 of 28

18. In which wiring installation is system earthing done?

Godown wiring

Domestic wiring

Substations

Commercial wiring

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Question 19 of 28

19. What test is carried out using a megger?

Earth electrode resistance test

Earth conductor continuity test

Polarity test

Insulation resistance test

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Question 20 of 28

20. Why is system earthing different from equipment earthing?

It protects humans only

It protects from all circuit faults

It's associated with current-carrying conductors

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

Question 20 of 28

Question 21 of 28

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

Earthing through impedance

Increasing conductor size

Providing plate earthing

Providing parallel earthing

Question 21 of 28

Question 22 of 28

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

1 MΩ

500 MΩ

Infinity

0 MΩ

Question 22 of 28

Question 23 of 28

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

 

Insulation resistance test between conductors and earth

Polarity test

Continuity (or) open circuit test

Insulation resistance test between conductors

Question 23 of 28

Question 24 of 28

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

Fleming's left hand rule

Self induction

Mutual induction

Fall of potential method

Question 24 of 28

Question 25 of 28

25. Advantage of stranded conductor over solid conductor?

More flexible

More insulation resistance

Cost is less

Less voltage drop

Question 25 of 28

Question 26 of 28

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

1.5 Sq.mm

3 Sq.mm

2.5 Sq.mm

3.5 Sq.mm

Question 26 of 28

Question 27 of 28

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

Short circuit between conductors

Open circuit in neutral line

High value series resistance fault

Open circuit in earth conductor

Question 27 of 28

Question 28 of 28

28. Why is AC supplied for earth resistance measurement?

Protect meter coils

Reduce meter current

Provide electrostatic shield

Avoid electrolytic emf interference

Question 28 of 28