Question: Ground resistance should be designed such that_____________?

• 1. grounding resistance should be as low as possible
• 2. grounding resistance should be as high as possible
• 3. grounding resistance should be always zero
• 4. none of the above

Question: When earth fault occurs______________?

• 1. voltage potential at the earth mat increases due to grounding
• 2. voltage potential at the earth mat decreases due to grounding
• 3. voltage potential at the earth mat remains zero irrespective of fault
• 4. none of the above

Question: Moisture content in the soil __________ the earth soil resistance?

• 1. increase
• 2. decrease
• 3. does not affect
• 4. none of the above

Question: For an EHV equipment for maintenance first it should be isolated and connected to ground because_____________?

• 1. to provide low impedance
• 2. to discharge the charging capacitance to ground
• 3. protection for operating personnel
• 4. both (B) and (C)

Question: The objective of earthing or grounding is_______________?

• 1. to provide as low resistance possible to the ground
• 2. to provide as high resistance possible to the ground
• 3. to provide flow of positive, negative and zero sequence currents
• 4. none of the above

Question: Factors on which soil resistance depends_______________?

• 1. depth of the electrode
• 2. moisture
• 3. Nacl
• 4. all the above

Question: Generally grounding is provided for:

• 1. only for the safety of the equipment
• 2. only for the safety of the operating personnel
• 3. both (A) and (B)
• 4. none of the above

Question: The size of the earth or ground wire is based on the______________?

• 1. maximum fault current carrying through the ground wire
• 2. rated current carrying capacity of the service line
• 3. depends on the soil resistance
• 4. both (A) and (C)

Question: There is a total of 800 mA of current into four parallel resistors. The currents through three of the resistors are 40 mA, 70 mA, and 200 mA. The current through the fourth resistor is______________?

• 1. 490 mA
• 2. 800 mA
• 3. 310 mA
• 4. 0 A

Question: If one of the resistors in a parallel circuit is removed, the total resistance_____________?

• 1. decreases
• 2. increases
• 3. remains the same
• 4. doubles