How should a voltmeter be connected in a circuit?

The proper way to connect a voltmeter in a circuit is by placing it in parallel across the component whose voltage you wish to measure. This configuration allows the voltmeter to measure the potential difference (voltage) across the component without affecting the overall circuit's operation. When a voltmeter is connected in parallel, it can accurately reflect the voltage while presenting a high resistance to the circuit, which minimizes the current that flows through the meter itself, ensuring that it doesn't load the circuit and alter the measurements.

In contrast, connecting a voltmeter in series with a load would lead to incorrect measurements because it would alter the current flowing through the circuit, thereby changing the voltage across the component. Placing it at the power source might not give accurate readings of voltage at other points in the circuit. Lastly, connecting a voltmeter in the ground path doesn't serve any purpose in measuring voltage since the ground path is typically at zero potential. Thus, connecting a voltmeter in parallel is essential for obtaining accurate voltage readings in electrical circuits.