Now-a-days different scholarships and professors want you to write a research proposal for scholarships. Such proposals are often not the exact and final one to proceed in your PhD. But the purpose of such proposal is putting a filter to non-serious students, who just apply for the sake of apply. And also to check the research aptitude skills of students. Here are good guidlines on how to write a proposal for MS and PhD admission. Have a read, if you want to have a one for yourself.