Unit 7

3. a force that causes certain materials to attract or repel each other.
8. a component that stores electrical energy in a circuit.
11. held small enough to be held and used in one hand.
16. the unique pattern of lines on the skin of a person’s finger.
18. a material that allows electricity to flow through it easily.
20. the ability of a system to store electrical charge.
22. a device that detects changes (like light, heat, or movement) and responds to them.
23. through metal detector a device people walk through to check for metal objects, often used at security checkpoints.
24. a component that limits the flow of electrical current.
25. a short, high sound made by an electronic device.
26. a wire wound into loops, often used to create a magnetic field.
28. induction a technology that uses short bursts of current to detect metal objects.

1. protection of people, places, or information from danger or crime.
2. zone an area where a device can sense or identify objects.
4. a very small electronic device that contains circuits and processes information.
5. a material that does not conduct electricity and is used to store energy in capacitors.
6. a system of video cameras used for surveillance and security.
7. a device that makes an electrical signal stronger.
9. scanning a method that uses electrical charge to detect touch or fingerprints.
10. done by hand, not automatically or by a machine.
12. to discover or identify the presence of something.
13. scanning using light to read or capture information (e.g., images or text).
14. a disturbance that affects a signal, making it weaker or unclear.
15. conductive not allowing electricity to pass through.
17. pulse a signal that bounces back after hitting an object.
19. field an area around a magnet or electric current where magnetic forces act.
21. a point where a wire or device is connected in a circuit.
27. scanning a method of identifying a person by analyzing the pattern in their eye.