Earthing Or Grounding MCQs

Option A: maximum fault current carrying through the ground wire

Option B: rated current carrying capacity of the service line

Option C: depends on the soil resistance

Option D: both (A) and (C)

Correct Answer: both (A) and (C) ✔

Option A: only for the safety of the equipment

Option B: only for the safety of the operating personnel

Option C: both (A) and (B)

Option D: none of the above

Correct Answer: both (A) and (B) ✔

Option A: depth of the electrode

Option B: moisture

Option C: Nacl

Option D: all the above

Correct Answer: all the above ✔

Option A: to provide as low resistance possible to the ground

Option B: to provide as high resistance possible to the ground

Option C: to provide flow of positive, negative and zero sequence currents

Option D: none of the above

Correct Answer: to provide as low resistance possible to the ground ✔

Option A: to provide low impedance

Option B: to discharge the charging capacitance to ground

Option C: protection for operating personnel

Option D: both (B) and (C)

Correct Answer: both (B) and (C) ✔

A. Increases
B. Decreases
C. Remains unaffected

Correct Answer: Increases ✔

Option A: increase

Option B: decrease

Option C: does not affect

Option D: none of the above

Correct Answer: decrease ✔

Option A: voltage potential at the earth mat increases due to grounding

Option B: voltage potential at the earth mat decreases due to grounding

Option C: voltage potential at the earth mat remains zero irrespective of fault

Option D: none of the above

Correct Answer: voltage potential at the earth mat increases due to grounding ✔

Option A: grounding resistance should be as low as possible

Option B: grounding resistance should be as high as possible

Option C: grounding resistance should be always zero

Option D: none of the above

Correct Answer: grounding resistance should be as low as possible ✔

Option A: 500 ohms

Option B: 1000 ohms

Option C: 1500 ohms

Option D: 2000 ohms

Correct Answer: 1000 ohms ✔