What happens if a voltmeter is connected in series with a circuit?

When a voltmeter is connected in series with a circuit, it does not function properly because voltmeters are designed to measure voltage differences across two points in a circuit by being connected in parallel. A voltmeter has a very high internal resistance, which allows it to measure voltage without significantly affecting the circuit's operation. However, connecting it in series introduces this high resistance into the circuit path, which disrupts the normal flow of current.

In a series configuration, the voltmeter would limit the current that can pass through it, leading to an inaccurate reading and potentially causing the meter to display a value that does not reflect the actual circuit voltage. This improper connection fundamentally compromises the voltmeter’s purpose, which is to measure voltage rather than impede current flow.