1.What do you mean by closed circuit?
2.How you make your own bulb?
3.give three examples of conductors and insulators?
4.Why is bulb said to be fused and why?
Answers
Answer:1 the circuit is closed when the electrical current can go through.
2
Round up the supplies needed for you bulb. Everything here is easy to round up at a local hardware store, if you don't already have it all at home. You'll need.
Two strands of copper wire (roughly 1-2 feet, each)
Four electrical clips
One clear glass jar
Five or more batteries
Find or buy some mechanical pencil lead. You should use the kind you get in mechanical pencils -- the thin, solo pieces of graphite that you can usually buy in packs. The thinner, the better -- try something like .5mm thickness.[1]
Pencil lead actually isn't lead at all, it is graphite. Graphite is an electrical conductor, making it a good filament for homemade light bulbs.
Hook the copper wires up to the electrical clips. The ends of each wire should have a clip on it. If you don't have clips, you can still make a light-bulb. To do so, curl each end of the wire into a little round hook.
If you are making the hooks yourself, make them big enough to fit over the end of the battery. Attach your batteries together in series. This simply means you tape them together, end to end, so that they all work together to provide power. Make sure you line them up positive end to negative end. Then use electrical tape to secure all the batteries together into a long rod.
Wrap the tape tightly enough around the batteries so that they hold together. You may need to overlap the tape a few times.
You must arrange the batteries so that there is a positive node on one end, and negative on the other.
5
Clamp a copper wire to one end of the batteries. Usually, you'll have a wire with red clips and one with black. Hook one end of the red clips up to the positive end of the batteries, but leave the other clip off for now. If you hook everything up, you'll actually be turning the light bulb on before you're ready. You could get burned if you're not careful
You can reverse the red and black if you want-- you just need different wires on each end.
Remember you only want to hook up one wire right now.
6
Stand up the two remaining clips, then clamp the graphite between them. Think of making an H-shape, where the two clips are the sides and the graphite is the horizontal line in the middle.[2]
The longer the graphite, the longer your bulb will last.
Use some tape, glue, or modeling clay to help stick the clips face up.
7
Put the glass jar on top of the clips and graphite. This isn't strictly necessary, as the graphite would still light even without the jar. But the process creates smoke, and the graphite can shatter. Moreover, having an actual "bulb" helps create a more even light.
The size of the jar does not matter, but the jar should be clean.
If the jar has a label, it would be a good idea to remove it; this will make it easier to see the light.
8
Attach the final wire to the other end of the batteries to turn the light on. You are making a simple circuit, connecting the batteries in an electrical loop. The light comes from the graphite -- as electricity flows through it, it heats up and emits energy in the form of light and heat. Thus, your light bulb!
9
Troubleshoot to get a stronger light. If the light is weak, or isn't working, there are some things you can do to make sure you get a working light.
Check the graphite thickness. While larger thicknesses work, 0.5 mm seems to work best.
Add a few more batteries. Also, make sure that the ones you have are touching end to end.
Make sure the wires are snug and well-connected to the batteries.
3)Conductors:iron, copper, steel
insulators:rubber, air, cloth
4)Because when the
tungsten filament is breaks the light bulb won't glow anymore.