The ground wire is coloured
- Green
- Black
- Yellow
- Red
Answer: – Option 1
The maximum permissible value of earth resistance for major substation is
- 0.5 Ohms
- 1 Ohms
- 2 Ohms
- 5 Ohms
Answer: – Option 2
Earthing is necessary to give protection against
- Danger of electric shock
- Voltage fluctuation
- Overloading
- High temperature of the conductors
Answer: – Option 1
The maximum permissible value of earth resistance for power station is
- 0.5 Ohms
- 1 Ohms
- 2 Ohms
- 5 Ohms
Answer: – Option 1
Solid grounding is adopted for voltages below
- 100 V
- 200 V
- 400 V
- 660 V
Answer: – Option 4
The maximum permissible value of earth resistance for minor substation is
- 0.5 Ohms
- 1 Ohms
- 2 Ohms
- 5 Ohms
Answer: – Option 3
The advantage of neutral earthing is
- Freedom from persistent arcing grounds
- Over voltages due to lightning can be discharged to earth
- Simplified design earth fault protection
- All of the above
Answer: – Option 4
The maximum permissible value of earth resistance for residential wiring is
- 0.5 Ohms
- 1 Ohms
- 5 Ohms
- 2 Ohms
Answer: – Option 3
The advantage of neutral earthing
- Safety of personnel
- Reduction of earth fault current
- Elimination of arcing ground
- None of the above
Answer: – Option 3
The maximum permissible value of earth resistance for H.T Line is
- 0.5 Ohms
- 1 Ohms
- 5 Ohms
- 10 Ohms
Answer: – Option 4
The maximum permissible value of earth resistance for L.T Line is
- 0.5 Ohms
- 1 Ohms
- 5 Ohms
- 2 Ohms
Answer: – Option 3
The maximum permissible value of earth resistance for Tower footing resistance is
- 10 Ohms
- 1 Ohms
- 5 Ohms
- 2 Ohms
Answer: – Option 1
The maximum permissible value of earth resistance for DTR structures is
- 10 Ohms
- 1 Ohms
- 5 Ohms
- 2 Ohms
Answer: – Option 3
If soil resistivity increases then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 1
If moisture content in soil increases then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 2
If earth electrode is buried deep inside the soil then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 2
If earth electrode is buried deep inside the soil then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 2
If earth electrode is buried deep inside the soil then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 2
If powder of charcoal and salt is added inside the soil then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 2
If electrode size is increased then earth resistance
- Increases
- Decreases
- Remains same
- Either 1 or 2
Answer: – Option 2
Earth resistance should be
- Low
- High
- Very High
- Either 2 or 3
Answer: – Option 1
Factors on which earth resistance depends are
- Depth of electrode
- Moisture
- Salt
- All of the above
Answer: – Option 4
Earth wire or ground wire is made of
1.Copper
2.Aluminium
3.Galvanised Steel
4.Iron
Answer: – Option 3
The size of earth wire or ground wire depends on
1.Rated current carrying capacity of the service line
2.Depends on the soil resistance
3.Maximum fault current carrying through the ground wire
4.Both (2) and (3)
Answer: – Option 4
Earth electrode used in plate earthing
- Plate
- Pipe
- Rod
- Grid
Answer: – Option 1
The material used in plate earthing
- Salt
- Charcoal
- GI wire
- All of the above
Answer: – Option 4
The size of plate electrode in inches in plate earthing is
- 0.25 inches
- 0.5 inches
- 0.75 inches
- 0.9 inches
Answer: – Option 1
The size of SWG for pipe earthing is
- 12 SWG
- 16 SWG
- 8 SWG
- 20 SWG
Answer: – Option 3
Which of the following is the cheapest method of earthing
- Pipe Earthing
- Plate Earthing
- Split Earthing
- Rod Earthing
Answer: – Option 3
The earth potential is taken as
- Zero
- Infinite
- 1 Volt
- 10 Volt
Answer: – Option 3