The viva was somewhat less stressful than some of the most important exams that I had passed (one of them being the driving exam, a fact that I still laugh about). Whether the reason laid in my poor memory (I could have forgotten how it was to be examined after six months) or overconfidence, I am not sure.
Before, there is cheering and question-guessing with your friends, but everyone knows that their time is about to come so the conversation is rather anxious. A viva lasts around half an hour. It takes certain skills to present your work in 7-10mins, especially if the topic is not yet well known amongst faculty staff. Fortunately, the three doctors seemed to listen and they did not interrupt while I was reaching the limits of my mouth’s words per second ratio.
Each examiner asked one question. For the first I was well prepared because he asked about tight binding and k·p band structure solving methods, which he taught us two years ago. The second asked about the definition of the angular momentum and its conservation law. It reminded me of my ever-returning plan to revise general physics, for my answer — albeit correct — was not as fluent as the first one. The third question was somewhat related to quantum cascade lasers. Although I knew that minibands emerge in superlattices, I had never given it a deeper thought and I only managed to answer fully with some help of the doctor who asked the question.
That was it. After a moment they called me back, announced the mark they gave me and congratulated on obtaining my first degree. I was pleased with the form of the examination: it was not black-and-white (i.e. either you know everything or you know nothing). If you struggled, they were there to point you in the right direction. They did not mean to show me how uneducated I was - which I heard was a normal attitude on a few other faculties. They smiled and were kind, for what I am grateful.