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

• A. Connect the ammeter in parallel across the component so it measures the voltage drop.
• B. Place the ammeter near the wire without opening the circuit; it will measure current via the electric field around the conductor.
• C. Connect the ammeter across the power supply terminals to measure the total available current without affecting the circuit.
• D. Insert the ammeter in series so the same current flows through the meter and the circuit element being tested.

Answer: (D)

Verified step by step guidance

1. Understand that an ammeter is designed to measure the current flowing through a circuit element, so it must be connected in such a way that the current passes through it.
2. Recall that current is the flow of electric charge, and in a series connection, the same current flows through all components connected one after another.
3. Recognize that connecting the ammeter in series with the component ensures that the current flowing through the component also flows through the ammeter, allowing it to measure the current accurately.
4. Note that connecting the ammeter in parallel would cause it to measure voltage instead, and could potentially damage the meter due to low internal resistance.
5. Therefore, to measure current correctly, insert the ammeter in series with the circuit element so that the current to be measured flows directly through the ammeter.