When the clamp meter is brought close to the wire, it shows a current of 0.2A even before the wire is clamped – is this induced current?

Yes, when the clamp meter is brought close to the wire but not yet fully clamped around it, it may display a small current value, which could be due to an electric current generated by electromagnetic induction. The alternating current in the wire generates a changing magnetic field, and the induction coil in the clamp meter may produce an induced current due to this changing magnetic field. In fact, a clamp ammeter uses Faraday’s law of electromagnetic induction to measure the current flowing through a cable. When an electric current flows through a cable, it creates a magnetic field in the surrounding space. The clamps of a clamp meter contain one or several windings that form a closed magnetic circuit. When this closed magnetic circuit is brought close to the cable, or the cable is placed within its loops, the alternating current in the cable induces a voltage in the windings of the clamp meter due to the magnetic field generated, allowing the current value to be read by the meter. If a clamp meter shows current even when no conductor is clamped, this could be caused by factors other than induced current, such as errors in the instrument itself, electromagnetic interference, or static electricity. To ensure the accuracy of measurements, the clamp ammeter should be calibrated to zero before use, and it is necessary to avoid being near other devices that generate strong magnetic fields. If unexpected readings continue to appear, it may be necessary to inspect or calibrate the clamp ammeter. .