Which instrument measures electrical voltage?

• A. Amp Meter
• B. Volt Meter
• C. Ohm Meter
• D. Blueprint/Schematic

Answer: (B)

Voltage is the potential difference between two points, and a voltmeter is used to measure that difference. A voltmeter is designed with high input impedance, so it draws very little current from the circuit and doesn’t significantly alter the voltage you’re trying to measure. You place it across the two points where you want to know the voltage, and the reading is given in volts (often with decimals for accuracy).

The other instruments measure different quantities: an ammeter measures current and is wired in series so the current flowing through the circuit passes through it; an ohmmeter measures resistance by applying a small current and observing the resulting voltage or vice versa; a blueprint or schematic is a diagram used to plan or interpret the wiring and does not measure electrical quantities.

In UPS work, you’d use a voltmeter to verify proper voltages at battery terminals, output rails, or AC input, ensuring everything is within specified ranges before powering up or during diagnostics.