8. After you've made your trouble light, decide on a good place to keep it where it will be handy for use. Loop it carefully and hang it over a wooden dowel rather than a nail. It will last longer.
[Illustration: Figure 1 Tying an Underwriter's Knot]
[Illustration: Figure 2 Disassembled Light]
1. A Junior Hard Service Cord is known as an (SO-Type) (SJO-Type) cord.
2. You disconnect a cord by (jerking it from the socket) (grasping plug and pulling it out).
3. Brass sockets are unsafe because (they break too easily) (the exposed metal can cause short circuits).
4. Rubber-covered cord is safer for emergency cords than fabric because (it will stretch) (it will insulate and protect the wires inside).
5. In a trouble light (any kind of bulb will do) (a rough service bulb is best).
1. Show how to make your trouble light and a method of storing it.
2. Show a safe trouble light, and an unsafe trouble light with danger points marked.
3. Show cutaway pieces of different types of cord.
Ask your power supplier, county highway engineer, police official or leader to tell you about various types of portable emergency lights and their uses.
What makes an electric motor run? Can you make an electric motor that will run? Certainly you can, and by doing so you'll learn why it runs. It won't be mysterious any more and you'll be ahead of all the millions of people who use motors every day and never know why or how the motor converts electrical energy into useful power.
You know how one end of a compass needle always points to North. No matter how you turn the compass, the same end of the needle always swings to the North. The earth itself and that small compass are both magnets (Figure 1). Each has a North pole and a South pole. Around the poles of each there are magnetic fields, invisible lines of force that attract and repel.
[Illustration: Figure 1. The same end of the compass needle always points to the earth's magnetic North Pole.]
The N poles _repel_ each other and so do the S poles. The N and S poles _attract_ each other. In other words, opposite poles attract; poles that are alike repel each other.
Lay 2 bar magnets on a table side-by-side. If both N poles are at one end, they'll repel each other and almost flip around until there's a N pole lying next to a S pole (Figure 2).