If you are physics student and you have very less time to do experiment in lab or. your lab doesn't provide a lot of instrument than don't worry. there are some application which help to understand the concept of physics easily. While doing preparation for my practical examination I had searched about it in internet, because we spent very little time on lab and have very poor knowledge about all practical application. But one website really helped me to learn about electronics instrument. The major feature of this application is you can view already given circuit or make your own circuit. and you can change all parameters also. To use this application you must have Java installed in your computer.  If you have proper internet connection and can surf net anytime than here is the link for this site.
but if you have not proper net connection than you can download the java application and can use it offline too. To download this application click below.
If you visit the homepage of this site you can find enormous application which may be useful to you.
So enjoy this applications and make yourself clear about electronics instrument.