Power System Planning and Design (2180903) MCQs

MCQs of Power system earthing

Showing 21 to 20 out of 30 Questions
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21.
Dimension of the copper strips used for the strip earthing is
(a) 25 mm × 3 mm
(b) 25 mm × 4 mm
(c) 30 mm × 3 mm
(d) 30 mm × 4 mm
Answer:

Option (b)

22.
________________ is also called ‘fire earthing’.
(a) Pipe earthing
(b) Plate earthing
(c) Strip earthing
(d) None of above
Answer:

Option (a)

23.
The size of the earth or ground wire is based on the
(a) Maximum fault current through the ground wire
(b) Rated current of the line
(c) Soil resistance
(d) Both (a) and (c)
Answer:

Option (d)

24.
Earth wire or ground wire is made of
(a) Copper
(b) Aluminum
(c) Iron
(d) Galvanized steel
Answer:

Option (d)

25.
Average resistance of human body is
(a) 500 Ω
(b) 1000 Ω
(c) 1500 Ω
(d) 2000 Ω
Answer:

Option (c)

26.
Ground resistance should be
(a) As low as possible
(b) As high as possible
(c) Zero
(d) None of above
Answer:

Option (a)

27.
During the maintenance of EHV equipment, first it isolated and connected with ground
(a) To provide low impedance path
(b) To discharge the charging capacitance to ground
(c) To protect operating personnel
(d) Both (b) and (c)
Answer:

Option (d)

28.
When earth fault occurs
(a) Potential of earth mat increases due to grounding
(b) Potential of earth mat decreases due to grounding
(c) Potential of earth mat remains zero
(d) None of above
Answer:

Option (a)

29.
Moisture content in the soil___________________the earth resistance.
(a) Increase
(b) Decrease
(c) Does not change
(d) None of above
Answer:

Option (b)

30.
Soil resistance depends on
(a) Moisture in soil
(b) Depth of the electrode
(c) Amount of salt mixed with soil
(d) All of above
Answer:

Option (d)

Showing 21 to 20 out of 30 Questions
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