What does a voltmeter measure?

What does a voltmeter measure?

• A. Measures current
• B. Measures voltage
• C. Measures resistance
• D. Measures temperature

Answer: (B)

A voltmeter measures electrical potential difference between two points in a circuit, i.e., the voltage. It’s wired in parallel across the component you want to test so it reads the same two points without steering a lot of current through the device. That parallel connection works because you want to sample the potential difference without disturbing the circuit, and voltmeters are built to present a very high input resistance to avoid drawing current. If you need to know how much current is flowing, you’d use an ammeter in series; to find resistance, you’d either apply a test voltage and measure resulting current or use an ohmmeter. In practical terms, you might measure the voltage across a battery or across a resistor to see how much potential difference exists, and the reading will be in volts.

A voltmeter measures electrical potential difference between two points in a circuit, i.e., the voltage. It’s wired in parallel across the component you want to test so it reads the same two points without steering a lot of current through the device. That parallel connection works because you want to sample the potential difference without disturbing the circuit, and voltmeters are built to present a very high input resistance to avoid drawing current. If you need to know how much current is flowing, you’d use an ammeter in series; to find resistance, you’d either apply a test voltage and measure resulting current or use an ohmmeter. In practical terms, you might measure the voltage across a battery or across a resistor to see how much potential difference exists, and the reading will be in volts.