To check electrical circuits, how is a voltmeter usually connected?

A voltmeter is designed to measure the voltage across two points in a circuit. To accurately measure this voltage, it must be connected in parallel with the component or section of the circuit you want to measure. This allows the voltmeter to read the potential difference without significantly altering the circuit's operation. When connected in parallel, the voltmeter can gauge how much voltage is available without drawing a noteworthy amount of current.

In contrast, an ammeter, which measures current, is connected in series with the circuit. This ensures that all the current flowing through the circuit passes through the ammeter, allowing for an accurate current measurement.

Options that propose alternate connections fail to facilitate proper voltage measurements or would disrupt the current flow, which is crucial in most electrical applications. Therefore, connecting the voltmeter in parallel and the ammeter in series is the correct approach to ensure reliable measurements in an electrical circuit.