Task 3. Check your answers to Task 3 with the help of the text and diagrams

Alternating current (AC) is applied to the coil in the search head from the battery in the control box. This creates an ever-changing electromagnetic field around the coil. An electric current is induced in any metal object the coil passes near.

The current induced in the metal object produces its own magnetic field, which in turn induces a voltage in the search coil, as the alternating current changes direction.

The circuitry in the control box senses this reaction and converts the voltage into an audible note, which is sent to the headset. As the metal object is approached, the sound in the headset becomes louder, or changes pitch.

Task 4. Label each step in this flowchart with the correct letter from the list.

The first one is done for you.