Which meter is designed to be connected directly across the power source and has very high resistance?

Which meter is designed to be connected directly across the power source and has very high resistance?

• A. Ammeter
• B. Voltmeter
• C. Ohmmeter
• D. Wattmeter

Answer: (B)

Voltmeter. It’s designed to be connected across the power source or across a component to measure voltage without drawing significant current. Its very high internal resistance minimizes the current drawn from the source, so the reading reflects the true voltage without loading the circuit. In contrast, an ammeter is placed in series and needs low resistance to avoid dropping voltage; an ohmmeter applies its own test current with the circuit unpowered; a wattmeter is configured to sense both current and voltage in a way that isn’t simply a parallel across the supply.

Voltmeter. It’s designed to be connected across the power source or across a component to measure voltage without drawing significant current. Its very high internal resistance minimizes the current drawn from the source, so the reading reflects the true voltage without loading the circuit. In contrast, an ammeter is placed in series and needs low resistance to avoid dropping voltage; an ohmmeter applies its own test current with the circuit unpowered; a wattmeter is configured to sense both current and voltage in a way that isn’t simply a parallel across the supply.