When measuring current, the meter must be placed in which arrangement with respect to the circuit?

• A. Across a resistor
• B. In series with the circuit
• C. Across the power supply
• D. In parallel with the circuit

Answer: (B)

Measuring current requires the meter to sit in the path of the current so that every ampere flowing through the circuit also flows through the meter. That's why the meter is connected in series with the load. An ammeter is designed to have very low resistance so it doesn't significantly affect the circuit or drop much voltage.

If you place the meter across a resistor, you’re effectively measuring the voltage drop across that resistor, not the current. Across the power supply would give you a current reading that doesn’t reflect the load path. Placing the meter in parallel with the circuit could create a near-short due to the meter’s low resistance in current mode, risking damage to the circuit and the meter.

So, the correct arrangement is in series with the circuit.