A viva is very different from a written exam because it does not allow you to make editions to your answer. You also do not have the option of skipping the difficult parts and answering difficult questions first. The key to ace the viva is to remain calm and composed and perform to the best of your ability even if you go wrong at some place.
While learning the subject, it may be helpful to remember facts in a way that makes them easy to remember and communicated in a viva. An intelligent, structured, cogent answer wins the points.
Here are few tips with which you can successfully give a good viva and get good marks.
Long Before The Viva
You might feel like you know everything included in the syllabus, or at least the most of it. However, it is on the actual day and time of viva that you realize that the breadth of questions. Consider reading the reports of previous examinations, talking to other candidates and joining a local study group to practise viva questions on each other.
Develop The Confidence
You can develop your confidence by answering the questions in class. Raise your hand and answer teacher's questions throughout the semester so that you know how it will feel like on the day of viva.
Your dress will set the first impression on the person who is taking the viva as you enter the room. Make sure that it is a good one. A formal shirt with trouser and tie should be good for men, whereas women can replace the trousers with a skirt. They can also go for a formal dress. Most of the times there isn't any requirement laid out in terms of dressing but giving importance to it can help your case.
Think of the possibilities of first few minutes before entering the viva room. If the person taking the viva gets up to greet you, you do not have any option other than shaking hands. Be mentally prepared for such a situation. Make sure your hands are not sweaty and too warm because that will give an impression that you are too nervous. Before going into the examination room find a cool surface, such as a wall or tabletop, and press your right hand against it in several places until the moment that you are called in. Then if you are forced to shake hands, yours at least will be cool and dry.
Enter the viva room an sit with straightened back so that you do not look slouchy. You may cross your ankles but not leg and never arms because it gives an impression that you do are not open to the viva taker's opinions and do not want to listen, in general. Maintain eye contact with the examiner. Even if one has asked the question, answer by looking at both of them so that they don't become uncomfortable. A good body language will take attention off your verbal errors to a large extent. If you have a tendency to wave hands, you can do that to exaggerate your point.
Answer The Question
The examiner are short of time so brevity would be appreciated by them. Explain your assignment in short time so that you can clarify things if your explanations are challenged by the examiner. Don't shy away from asking for clarification if you do not understand a question. ask for it to be rephrased with phrases like: ‘I’m sorry, would you like me to tell you about...?’ If you are asked several questions at once, the examiner is clearly at fault: pick one of the questions that you are happy with and answer that. If you cannot respond, say so early with a use of words that suggests that, although you cannot immediately recall the answer, you do know really.
At some point, examiner might ask a 'heart sink' question. A heart sink question is the one which has an easy answer but is unanswerable at that exact moment. There is no good way of responding to a heartsink question, by definition, so think of as many as possible before you go into the exam. If, however, you are asked, say, ‘What fungi are of surgical importance?’ and cannot think of a single one, you might try ‘Well, there are lots. Which one would you like me to start with?’. When the examiner suggests you start with Candida albicans, at least you will get a handhold on the question.
At The End Of Viva
Avoid saying things like 'I’m sure I could have done better’ as it invites the response ‘Yes, I’m sure you could’. Leave the room as your time with the examiner gets over so that they mark you easily as you are not within their range of hearing.
With so many aspects covered, remember not to attach more importance to a viva than you should so that you are not stressed out by the thought of it.