What is the sequence for testing current in an AC or DC circuit?

The selected answer outlines the proper procedure for measuring current in an AC or DC circuit, ensuring both accuracy and safety. The sequence begins with turning off the circuit, which is a critical first step to prevent accidental shock or damage to the measuring instrument. Next, connecting the probes in series is necessary because current is measured through the circuit; placing the ammeter in series allows it to measure the flow of current accurately as it flows through the circuit.

After the probes are connected, turning on the power is essential to enable current flow so that an accurate reading can be taken. Taking the reading while the circuit is powered provides real-time data on the current, which is crucial for diagnostics or performance checks. Finally, turning off the power again after taking the measurement is important for safety, ensuring that any adjustments or disconnections can be done without risk.

Other options do not represent the best practices for measuring current. Connecting probes without first ensuring the circuit is off could lead to dangerous situations. Additionally, measuring current without disconnecting the circuit properly may not yield accurate results. Therefore, the outlined sequence in the correct choice effectively prioritizes safety and precision in current measurement.