Which instrument is designed to be connected in parallel with the element under test?

Which instrument is designed to be connected in parallel with the element under test?

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

Answer: (A)

When you want to read the voltage across a component, you connect the measuring device in parallel with that component. The voltmeter is built to have a very high input impedance, so it draws only a tiny current. That keeps the circuit’s operation essentially unchanged while you measure the voltage across the element. If you put an ammeter in parallel, its low resistance would create a short path and disrupt the circuit, which is why ammeters are placed in series to measure current. An ohmmeter is used to determine resistance, usually with the power off, by applying a small test signal across the element, and it’s not used to measure voltage in a live circuit. A wattmeter combines voltage and current sensing to measure power, and its internal design reflects that dual purpose rather than a simple parallel connection for voltage alone. So the instrument intended to be connected across the element to measure voltage is the voltmeter.

When you want to read the voltage across a component, you connect the measuring device in parallel with that component. The voltmeter is built to have a very high input impedance, so it draws only a tiny current. That keeps the circuit’s operation essentially unchanged while you measure the voltage across the element.

If you put an ammeter in parallel, its low resistance would create a short path and disrupt the circuit, which is why ammeters are placed in series to measure current. An ohmmeter is used to determine resistance, usually with the power off, by applying a small test signal across the element, and it’s not used to measure voltage in a live circuit. A wattmeter combines voltage and current sensing to measure power, and its internal design reflects that dual purpose rather than a simple parallel connection for voltage alone.

So the instrument intended to be connected across the element to measure voltage is the voltmeter.