hi, I am new to iPad,I am having iPhone distribution build, can i upload to apple for iPad Device?Will it run? will it be accepted by Apple?otherwise i have to create new Ipad application for existing iphone application?
Practically all iPhone apps will run unmodified on the iPad. They will simply be scaled up pixel-by-pixel (with a little "2x" button so the user can choose scaled/unscaled mode).
For the best user experience, you should create a universal binary that provides customised behaviour for each platform, but this isn't required.
Any iPhone application, an application that has not been optimized for the iPad, will run on the iPad in 'compatibility mode', which means it will get its own iPhone-sized frame in the center of the iPad screen. The user also has the option to zoom in the application 2 times, so it takes up almost the entire iPad screen.
So if you want your app to run at all on the iPad, you don't have to do anything exciting, just submit it to Apple as usual, and iPad users will be able to download and use it.
If you want to optimize your application for the iPad, which is almost always preferred over 'compatibility mode', you can either make your current application into a Universal one, which is an app which contains both iPhone and iPad versions, in one binary, or you can create two different applications, one for the iPhone and one for the iPad. You can find more information on this on the Apple Developer website.