Nate Electrical Practice Exam

A voltmeter is connected into a circuit in which of the following ways?

1. Series

2. Parallel

3. Series-parallel

4. Delta

The correct answer is: Parallel

A voltmeter is specifically designed to measure the potential difference (voltage) across two points in an electrical circuit without significantly affecting the overall circuit operation. To achieve this, it must be connected in parallel with the component or section of the circuit where the voltage is to be measured. When a voltmeter is connected in parallel, it allows for the measurement of the voltage drop across the component while maintaining the same potential at both terminals of the voltmeter. This configuration ensures that the voltmeter does not change the current flowing in the circuit significantly because it has a very high internal resistance. This high resistance prevents the voltmeter from drawing substantial current, which could otherwise alter the voltage reading and affect the circuit's performance. In contrast, connecting a voltmeter in series would lead to incorrect readings, as the voltmeter would become part of the main circuit and influence the total current flowing through the circuit, thereby changing the voltage it is intended to measure. The series-parallel and delta configurations are not standard methods for connecting a voltmeter, as they do not allow for accurate voltage measurements across components. Thus, the parallel connection is the correct method, ensuring the voltmeter measures voltage accurately without disrupting the circuit.