Other groups on this forum seem to be filled with requests on seminar topics. And getting ready answers to your homework questions.
Posting those question to other groups is not generally a good idea and easily annoys other users. You can easily get answers like "wh you are asking for ready answer, you should do your homework yourself!
This is the right place for posting this kind of questions. If those questions have anything to do with the topics coverd by this site (anyting related to electrics, electronics, computers etc..) then they are here in the right place.
When doing a school home work, it is the best that you first really try to solve your problem youself. The homework assignments are for your best. You will learn when you do them yourself. If you just look for ready answers, you will not learn how to solve problems yourself.
If you have really tried yourself, and still do not get the problem, then it might be a good idea to ask help here. There could be someone friendly reader who can use some of their time to give you some useful tips..
When looking for answers, it is still usually best to go to the library use the actual printed works that have necessary information. But there are times when you don't have one handy and the libraries and stores are all closed. Internet can also be useful information resource. Usually if you have right keywords, Internet search engines can do wonders.
It is generally a good idea to check www.epanorama.net site search at http://www.epanorama.net/multi.php and Google seach at http://www.google.com/
When using Internet information resources, remeber that not everything you find in Internet is true.
If you have tried all those methods, and still did not get the answer to your problem, then posting a good question here could propably help.