How to run index.php file in amazon EC2?

I have been newly introduced to AMAZON EC2 Server, recently I have created a micro instance EC2 Ubuntu and have installed Apache, PHP and MySql. I have some PHP files including an index.php. I have uploaded my files to /var/www/html directory. Now when i open my Public DNS in browser it shows nothing. The same thing is working in my localhost setup. Is there something enabling mod rewrite in EC2 Ubuntu instance ?

Please help.

Thanks in advance.