Why is a voltmeter connected in parallel to measure the voltage across a component?

Why is a voltmeter connected in parallel to measure the voltage across a component?

• A. To measure the voltage across the component
• B. To allow more current through the circuit
• C. To measure current
• D. To store charge

Answer: (A)

A voltmeter is used to measure the potential difference between two points. To measure the voltage across a component, you place it in parallel with that component so it taps into the same two nodes and reads the same voltage as across the component. A voltmeter is designed with very high resistance, so it draws almost no current and doesn’t noticeably disturb the circuit. If it were placed in series, it would have to carry current and would alter the circuit, giving an incorrect reading. It’s not for measuring current (that’s what an ammeter does), and it doesn’t store charge (that’s the role of a capacitor).

A voltmeter is used to measure the potential difference between two points. To measure the voltage across a component, you place it in parallel with that component so it taps into the same two nodes and reads the same voltage as across the component. A voltmeter is designed with very high resistance, so it draws almost no current and doesn’t noticeably disturb the circuit. If it were placed in series, it would have to carry current and would alter the circuit, giving an incorrect reading. It’s not for measuring current (that’s what an ammeter does), and it doesn’t store charge (that’s the role of a capacitor).