146 S13 Grounding Material

What is a key characteristic of a good grounding system?

• a) High electrical resistance
• b) High electrical conductivity
• c) Low mechanical strength
• d) High impedance

What is one of the main purposes of a grounding system?

• a) To increase electrical resistance
• b) To limit transient overvoltage
• c) To disconnect the power supply
• d) To store electrical energy

Which of the following is NOT a component of a grounding system?

• a) Grounding conductors
• b) Grounding connectors
• c) Grounding electrodes
• d) Grounding insulators

What is the NEC requirement for grounding electrode resistance?

• a) Under 25 ohms
• b) Over 50 ohms
• c) Exactly 30 ohms
• d) Under 10 ohms

Which material is NOT allowed for use as a grounding electrode?

• a) Copper
• b) Aluminum
• c) Steel
• d) Bronze

What can accelerate corrosion in grounding systems?

• a) High voltage
• b) Presence of moisture
• c) Low temperature
• d) Lack of oxygen

What combination of materials must be avoided in grounding systems to prevent electrolytic couples?

• a) Copper and steel
• b) Copper and bronze
• c) Aluminum and zinc
• d) Steel and iron

What should be done to down conductors entering corrosive soil?

• a) They should be insulated
• b) They should be protected with a covering
• c) They should be made of aluminum
• d) They should be shortened

Which material is most suitable for grounding systems due to its conductivity and corrosion resistance?

• a) Steel
• b) Copper
• c) Aluminum
• d) Zinc

What type of ground electrodes are metal underground water pipes?

• a) Made electrodes
• b) Natural electrodes
• c) Synthetic electrodes
• d) Temporary electrodes