Many homeowners take steps to ensure that their home is not an easy target for burglars. How? They install a burglar alarm. Do you know a burglar alarm works? Both magnets and electric circuits are involved.
The Back Story
- When a burglar alarm system is turned on, the alarm starts ringing loudly if a door is opened. Opening the door either closes or opens an electric circuit. This, in turn, causes the alarm to ring.
- You can see how one type of burglar alarm works by watching this video of a middle school science fair project:
Show What You Know
Learn more about burglar alarms by reading the first page at the link below. Then answer the questions that follow.
- Describe the science fair burglar alarm in the video above.
- Explain how the science fair burglar alarm works.
- Compare and contrast open-circuit and closed-circuit burglar alarms.
- Which type of alarm—open-circuit or closed-circuit—is the science fair alarm? What is a disadvantage of a closed-circuit alarm?
- Besides doorways, where can burglar alarms be installed?