The size of the earth or ground wire is based on the______________?
(A) maximum fault current carrying through the ground wire
(B) rated current carrying capacity of the service line
(C) depends on the soil resistance
(D) both (A) and (C)
Generally grounding is provided for
(A) only for the safety of the equipment
(B) only for the safety of the operating personnel
(C) both (A) and (B)
(D) none of the above
Factors on which soil resistance depends_______________?
(A) depth of the electrode
(B) moisture
(C) Nacl
(D) all the above
The objective of earthing or grounding is_______________?
(A) to provide as low resistance possible to the ground
(B) to provide as high resistance possible to the ground
(C) to provide flow of positive, negative and zero sequence currents
(D) none of the above
For an EHV equipment for maintenance first it should be isolated and connected to ground because_____________?
(A) to provide low impedance
(B) to discharge the charging capacitance to ground
(C) protection for operating personnel
(D) both (B) and (C)
Moisture content in the soil __________ the earth soil resistance?
(A) increase
(B) decrease
(C) does not affect
(D) none of the above
When earth fault occurs______________?
(A) voltage potential at the earth mat increases due to grounding
(B) voltage potential at the earth mat decreases due to grounding
(C) voltage potential at the earth mat remains zero irrespective of fault
(D) none of the above
Ground resistance should be designed such that_____________?
(A) grounding resistance should be as low as possible
(B) grounding resistance should be as high as possible
(C) grounding resistance should be always zero
(D) none of the above
Average resistance of human body is____________?
(A) 500 ohms
(B) 1000 ohms
(C) 1500 ohms
(D) 2000 ohms
Three 47 Ω resistors are connected in parallel across a 110 volt source. The current drawn from the source is approximately_______________?
(A) 2.3 A
(B) 780 mA
(C) 47 mA
(D) 7.06 A