______ eliminates spark discharges between two conductors.

• A. Grounding
• B. Insulation
• C. Bonding
• D. Shielding

Answer: (A)

Spark discharges happen when there’s a large voltage difference between conductors or between a conductor and the surrounding air. Grounding ties conductors to the earth, giving them a common reference potential and a low-impedance path for fault currents. With that earth reference, the potentials of the connected conductors are kept essentially equal, so the voltage difference that would cause arcing is minimized and spark discharges are prevented in fault or near-contact situations. Insulation blocks current but doesn’t equalize potentials, so two insulated conductors can still have a dangerous voltage difference. Shielding mainly reduces exposure to electric fields, not the likelihood of arcing between conductors. Bonding reduces potential differences between metal parts but grounding provides the direct earth reference and fault-path safety that most effectively eliminates spark discharges.