You did not say which version of iPad you have (the first or second generation). For an iPad2, the stock answer is no, you cannot restore to iOS version 5.0. Apple has closed the window for access to that firmware and the only firmware available is 5.0.1. When you do a restore, that is the version that will be put onto your iPad2.
If you have an iPad1, there is a chance you may be able to restore using iOS 5.0. But, only if you have an iPad1.
Marilyn