Advanced Qualification · A-003 Measurements · A-003-006-003
A voltmeter having a range of 150 volts and an internal resistance of 150 000 ohms is to be extended to read 750 volts. The required multiplier resistor would have a value of:
- A 1 500 ohms
- B 750 000 ohms
- C 1 200 000 ohms
- D 600 000 ohms
Correct answer: D — 600 000 ohms. From the official ISED question bank, verified word for word.
Why
To reach 750 volts from a 150 volt limit, you must drop the extra 600 volts across a new resistor while keeping the same tiny current flowing through the meter. 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.