For a science project, I have chosen to make a rheostat, But something isn't working?
Answer:
There is not enough resistance to decrease the current flow. If you used regular wire for the reostat, you will never get it to work. If you use nicrome wire, you will have a better chance. Go to a second hand shop, or flee market, and buy an old electric heater with the spring style heating element. Use this spring wire for your resistive element. It is nickel, and chrome(hence nichrome) and highly resistive. Also, your increasing the load (number of bulbs) could be throwing your circuits' balance off. Use a batery/ bulb combination that came in the flashlight you got your parts from. flashlight bulbs are very sensitive to their designed power requirements. Next, follow the instructions on the website as closely as you can, then experiment with modifications after you got it to work. Hope this helps
If the wire in your spring is too big or the spring is too short, the maximum resistance will be too low to make a noticeable difference in the light output. Are your light bulb in series? it they are, you might try using just one battery and one bulb so that the resistance of your rheostat is a larger fraction of the total circuit resistance.
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