# physics projects

#### wire

Joined Dec 18, 2011
13
Guys........I need a suggestion on physics projects (modals) related to .....capacitors , electromagnetic waves , light or resistors which can be displaced for BSE level but not too complicated as it is not major subject .

#### R!f@@

Joined Apr 2, 2009
9,890

#### wire

Joined Dec 18, 2011
13
The reference site was quite useful.The problem is that I am running short of time I need I project which can be displayed .....the topic I have studied are about capacitors,resistance,electricity,electromagnetic waves....circuits....All experiment I have seen I think they can not be tagged as projects......I need some proper but simple to implement project....

#### Sparky49

Joined Jul 16, 2011
833
You could investigate the construction and use of a simple time domain reflectometer.

I'll breifly explain what one is.

If you have a long length of buried cable (we're talking into the hundreds of meters long) which transmits data, you're in a spot of bother if it becomes damaged because of a short circuit, a cut, water etc...

You can't really justify digging up hundreds of meter of cable to find one fault, especially if it's in a residential area - think of all the complaints!

Instead you can exploit an interesting effect - that some energy will reflect from the damaged part of the cable, back towards the emitter!

This is what a time domain reflectometer (TDR) relies upon. At a basic level, it emits a large pulse of energy and waits for the reflection. You can time how long it takes for the pulse to go out and be reflected. With a bit of maths you can figure out where the damage is (to within a few meters!).

Resistance and capacitance are covered nicely as both resistors and capacitors are used to generate the out going pulses - and can be used to vary the length of the pulse.

Electricity is covered because - well - it runs off the stuff. Also, it ties in nicely with electricity in communications.

If this suits you, I can provide a website with some more infomation to get you started.

But you'll have to say please first!

Sparky

#### studiot

Joined Nov 9, 2007
4,998

You could investigate the construction and use of a simple time domain reflectometer.
There were a couple of good articles on this in a recent Elektor magazine including a practical project to follow.

Metal detectors, cable detectors etc are also good for practical projects.

Also visit this site

www.physicsforums.com

go well

#### wire

Joined Dec 18, 2011
13
please ..... but i hope it will not be too complicated......as I think it will be.Would I be able to implement it.
I was thinking to make a working model. ...using vegetable to generate electricity to lit a led to make traffic light but I think your idea will be a better choice.

#### wire

Joined Dec 18, 2011
13
I can implement the circuit which I have seen .It involved oscilloscope and source generator. I have to study alot for understanding its working.Physics is not my major subject.I am doing software engineering.I think now you would be understand that I have only surface knowledge of physics.The site is

http://www.epanorama.net/circuits/tdr.html

#### Sparky49

Joined Jul 16, 2011
833
The time domain reflectometer is probably simpler than the traffic lights circuit.

Vegetable batteries are such a - cliche. They've been done and done and done and done and done and....

http://www.free-circuit.com/time-domain-reflectometertdr-circuit-with-74ac14/

Also, as studiot says, there are a few recent articles from elektor, which can be bought for virtually nothing. Regardless of their cost - they'll help you produce a brilliant project.

Here's the link to the first article, discussing the whole idea of time domain reflectomy:

http://www.elektor.com/magazines/2011/october/time-domain-reflectometry.1948603.lynkx

And here's another about making the actual TDR:
http://www.elektor.com/magazines/20...cilloscope-into-a-reflectometer.1992172.lynkx

Sparky

P.S. If you want any more help, don't be afraid to ask!

P.P.S. I guess you are taking a GSE?

#### Sparky49

Joined Jul 16, 2011
833
I can implement the circuit which I have seen .It involved oscilloscope and source generator. I have to study alot for understanding its working.Physics is not my major subject.I am doing software engineering.I think now you would be understand that I have only surface knowledge of physics.The site is

http://www.epanorama.net/circuits/tdr.html
Good website - I was looking for that one!

Have a look at the Elektor articles - what part of the world are you from?