A voltmeter is typically connected in which configuration to measure the voltage across a component?

• A. In parallel with the component
• B. In series with the component
• C. Across the power supply only
• D. Across the entire circuit

Answer: (A)

Measuring voltage relies on reading the potential difference between two points, so a voltmeter must be connected across the two terminals of the component. Placing it in parallel with the component ensures it experiences the same voltage drop as the component, while its high internal resistance minimizes any current drawn from the circuit and avoids disturbing the circuit’s operation. If it were placed in series, it would alter the current path and not provide a true measure of the component’s voltage drop. Connecting across the power supply or across the entire circuit would show the supply or total circuit voltage, not the voltage specific to that component.