Can someone suggest a few science experiments we could do at our school for the Science Exhibition ?
Welcome to the PF.
You said in your New Member Introduction post that you are in high school. What kinds of experiments/projects have been done in the past? Have you done a search online for High School Science Fair Projects? You will get hundreds (if not thousands) of suggestions.
What are your favorite areas of science? Physics? Chemistry? Biology? Engineering/Robotics?
My first science fair project was a volcano, my first experiment was a little cup filled with salt water, sprinkle some pepper on top of the salt water and insert a charged rod, electrochemistry! I think I picked that one up in Mr wizards science secrets.
Yes I have done so but the topics seem either extremely simplistic or require great amount of knowledge in electronics and other fields. I would like to do something in electricity and optics.If you could give me some chemistry topics as well I would be really happy.
Take a flashlight and a prisim and explain how the light splits into different wavelengths according to the angle of incidence in the prisim.
Electro-optic modulation of a laser pointer beam to
Well, a fun one is to use 2 audio speakers and light first-surface mirrors (FSMs) to make an x-y laser pointer deflection system. You need to figure out how to mount one end of the mirror to the center of the dust cap in the speaker and the other end to some sort of hinge mechanism near the edge of the cone (which is fixed with respect to the speaker enclosure). That way, as the speaker cone vibrates in and out, the FSM rotates about that hinge. An even better arrangement is to figure out some mechanical mechanism that attaches to the dust cover and the edge of the speaker, and allows the mirror to rotate like a teeter-totter so that the middle of it is just changing angle and not moving in and out with the speaker cone.
Use a low-power laser pointer to bounce off the center of the two mirrors, and arrange the speakers so that they provide x & y deflection of the beam. Be careful to aim the beam at a safe surface so that there is no chance of anybody getting a strong reflection in their eye. Then drive the two speakers with simple tones or more complex waveforms to see that kind of patterns you can make. You could probably use the stereo output from your cellphone (or two cellphones) with a signal generator App to generate the tones to feed to the (externally powered) speakers.
EDIT/ADD -- You want to place the 2 mirrors as close together as possible, to reduce the position error on the 2nd mirror. Here is the basic construction of most audio speakers for reference:
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