Which statement best distinguishes a dead test from a live test during insulation verification?

• A. Dead test checks continuity and resistance without power; live test checks insulation resistance with a test voltage applied under controlled conditions.
• B. Dead test checks insulation resistance with a test voltage; live test checks continuity and resistance without power.
• C. Dead test checks earth continuity; live test checks polarity.
• D. Dead test checks voltage; live test checks current.

Answer: (A)

The key idea is to distinguish tests done with the circuit de-energized from those done with voltage applied, and what each test measures.

In a dead test, the equipment is disconnected from power, so you can safely check the wiring path and its basic electrical properties. This means verifying continuity (is there a complete path between points?) and measuring resistance to confirm there are no open circuits or unexpected breaks in the conductors. No external voltage is applied during this test.

A live test, on the other hand, involves applying a test voltage to the insulation under controlled conditions while the system is energized or prepared to operate. The purpose is to measure insulation resistance and detect leakage paths that might only become evident under voltage, ensuring the insulation can withstand the operating voltage.

So the statement that best fits is that a dead test checks continuity and resistance without power, while a live test checks insulation resistance with a test voltage applied under controlled conditions. The other choices mix up what is tested or whether power is present.