Hello Madhuri,
In computer based test you have to solve questions on computer in online mode.
As soon as you enter in the exam hall i.e. computer lab ,examinars will give you instructions regarding does and don't s based on API design for the examination many times it includes guidelines such as ' don't close tab while examination is going on' or ' don't open another tab',' click on submit button after you tick the answer' etc.
All the guidelines are given on Portal before exam starts and you must read them properly and keep in mind while solving the exam.
In computer based exams as the time limit is fixed digitally on computer you won't receive a single minute more than decided time so manage your time wisely.
Hope this helps.
All the Best.
You have not mentioned here which exam you are talking about so I cannot specifically help you with that. But in general you can practice for mock tests on your computer and get aquainted with the procedure. Many exams like JEE Mains conducts practice test centres where you can go and get aquainted with the user interface of the actual exam.
Hope this helps. Good luck!
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