Question

can some one please explain

Answer 1

This is a computer science question. If you post this category of questions at the CS section, you will be more likely to have a faster response.

An interrupt is to stop executing the current process in order to attend to a higher priority process. After the higher priority process (interrupt) is terminated, execution resumes at exactly where it left off. This is achieved by saving the state of the process (contents of registers, program counter, etc.) and reloading it when the process resumes processing.
The diagram pretty much explains exactly the same thing.

For more reading, use your text book, or try
http://en.wikipedia.org/wiki/Interrupt

Answer 2

thanks can you please check my answer

Answer 3

Sorry, I don't open Word files.
Can you post a snapshot? Thank you.

Answer 4

I think the important point here is while switching context, you need to save the state of P0, and load the state of P1. Same when switching back from P1 to P0.
Apart from the above, it's a good description of the situation.