Question 291Electricity & Electronics - QMED

The correct answer is A) must be fully closed so as to complete the magnetic circuit. For a clamp-on ammeter to take an accurate current reading, the jaws of the instrument must be fully closed around the conductor. This completes the magnetic circuit within the ammeter, allowing it to accurately measure the current flowing through the conductor. If the jaws are not fully closed, the magnetic circuit will be incomplete, and the ammeter will not be able to provide an accurate current reading. The other options are incorrect because: B) holding the jaws so they don't touch a conductor would prevent the ammeter from taking a reading; C) the jaws must be closed to complete the magnetic circuit; and D) the ammeter only needs to be clamped around a single conductor, not all conductors in a cable.