Technician exam question T7D05
Subelement T7, PRACTICAL CIRCUITS· Group T7D
How does an ohmmeter measure the resistance of a circuit or component?
- A.By applying a small current and measuring the resulting voltage (correct answer)
- B.By placing a variable resistor in parallel with the circuit
- C.By placing a variable resistor in series with the circuit
- D.By applying a variable voltage and measuring the resulting current change
WhyAn ohmmeter measures resistance by applying a small current and measuring the resulting voltage. An ohmmeter works by applying a small, known current from its own internal battery through the component being tested and measuring the resulting voltage drop, then calculating resistance from that relationship, answer A. It doesn't add a variable resistor in parallel (B) or series (C) with the circuit under test, and applying a variable voltage while measuring current (D) describes a different kind of test setup, not how a simple ohmmeter works.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.
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