How to get a good Quality score

[ppsinfo]

Also does PR affect the search results , i have my website which has 0 PR but sometimes is shown on first page for few keywords
Do i need to use different keywords in Adwords , and start new campaign

[cathy duncan]

Yeah sure, addition of new KWs would certainly be a great plus for your website. In my opinion, you should use a mixture of low and high search volume KWs to maintain and accelerate your PR.