In an electric circuit, how is current measured using an in-line (series) ammeter?

• A. By placing the ammeter across the power supply terminals to measure the supply voltage directly
• B. By connecting the ammeter in parallel across the component so it measures the voltage drop
• C. By inserting the ammeter in series with the component so the same current flows through the meter and the circuit element
• D. By connecting the ammeter to ground and measuring the electric field around the wire

Answer: (C)

Verified step by step guidance

1. Understand that an ammeter is a device used to measure the electric current flowing through a circuit.
2. Recall that current is the flow of electric charge through a conductor, and to measure it accurately, the measuring device must experience the same current as the circuit element.
3. Recognize that to achieve this, the ammeter must be connected in series with the component whose current you want to measure, so the current flowing through the component also flows through the ammeter.
4. Note that connecting the ammeter in parallel or across the power supply terminals is incorrect because it would measure voltage or cause a short circuit, not current.
5. Therefore, the correct method is to insert the ammeter in series with the component, ensuring the same current passes through both the component and the ammeter for an accurate measurement.