'Live-dead live' test is used to:

• A. Detect live wires
• B. Measure voltage
• C. Verify a circuit is de-energized
• D. Check grounding

Answer: (C)

This question tests safety verification that a circuit is de-energized before work. The live-dead live check is used to confirm that a circuit is truly de-energized by first testing a known live source to ensure the tester is functioning, then applying it to the circuit to see if it shows no voltage, and finally re-testing on a live source to confirm the tester hasn’t failed. This approach focuses on proving de-energization and readiness for safe work, rather than simply detecting live wires, measuring actual voltage on a live circuit, or checking grounding.