Another reason why prospective candidates are required to submit a research proposal as part of an application for admission is because it formally outlines your intended research.
Could it be that you're interested to see how a particular theoretical approach could be adapted or extended, tried or tested in new and innovative ways?
A research proposal aims to present your idea or your question and expected outcomes with clarity and definition – the what.
Your proposal is less of a contract and more of a guide – a plan for your research that is necessarily flexible. But it's worth checking the details of what's required from your specific faculty and degree with your supervisor or the relevant postgraduate research coordinator.
Presenting your idea clearly and concisely demonstrates that you can write this way – an attribute of a potential research candidate that is valued by assessors.
A brief but clear summary of what your research is about.
It outlines the key aspects of what you will investigate as well as the expected outcomes.
Make sure that this is a clearly focused statement.
Your objectives will be your aim broken down – the steps to achieving the intended outcome.
It also seeks to make a case for the reason your question is significant, the value add that your research will bring to your discipline – the why.
What it shouldn't do is answer the question – that's what your research will do.