Extra exam question E4B02
Subelement E4, AMATEUR PRACTICES· Group E4B
What is the significance of voltmeter sensitivity expressed in ohms per volt?
- A.The full scale reading of the voltmeter multiplied by its ohms per volt rating is the input impedance of the voltmeter (correct answer)
- B.The reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
- C.The reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
- D.The full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
WhyA voltmeter's sensitivity in ohms per volt, multiplied by a range's full-scale voltage reading, gives the meter's input impedance on that range. A voltmeter's sensitivity, expressed in ohms per volt, tells you its input impedance on a given range: multiplying that range's full-scale voltage reading by the ohms-per-volt rating gives the meter's input impedance on that range, a figure that matters because a low-impedance meter can load down and distort the circuit it's measuring, answer A. The other options describe unrelated calculations, power draw, applied voltage, or shunt sizing, that aren't what ohms-per-volt sensitivity is used to find.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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