Advanced Qualification · A-003 Measurements · A-003-001-007
AC voltmeter scales are usually calibrated to read:
- A peak voltage
- B instantaneous voltage
- C average voltage
- D RMS voltage
Correct answer: D — RMS voltage. From the official ISED question bank, verified word for word.
Why
AC voltmeter scales show RMS voltage because this value tells you the equivalent direct current that would produce the same heating effect in a resistor. The full explanation — and one for every question — is in Pro.
Practise this section
Measurements: meters, oscilloscopes, counters, signal generators, and what a reading actually tells you.