To ________ a circuit or apparatus, means to connect it to earth.

• A. ground
• B. energize
• C. isolate
• D. insulate

Answer: (A)

Grounding a circuit or apparatus means connecting it to earth to establish a reference potential and give fault currents a safe, low-impedance path to follow. This connection keeps exposed metal parts at earth potential, so if insulation fails or a fault occurs, the current flows directly to the ground and protective devices (like fuses or breakers) can trip quickly, reducing the risk of electric shock. It also helps stabilize voltage levels during transients.

The other actions describe different operations: energizing applies voltage to run the circuit; isolating means separating it from power or the rest of the system; insulating involves covering conductors to prevent current flow. None of those describe the act of connecting to earth, which is what grounding encompasses.