I am an undergrad student with Physics Major, currently in my last year. I'm from India, and recently I have given my first interview for an integrated Ph.D. in Physics. And there are several interviews that are ahead of me.

What I need to know is this: suppose the interviewer asks a student a question, which is off-topic that is to say, rarely thought of at the undergraduate level in any of the universities. The student might simply say, "I don't have a knowledge of the topic as we haven't learned this in our undergrad course." Or there are some students who go beyond their course and learn the topic by themselves. So suppose another student gives the answer to the same question because they learned it by themself. Can the interviewer judge the students based on this question? Is there any advantage for student B to read stuff that is out of the course?


Saying you don't know the answer to a question is poor interview technique regardless of the situation.

Of course, you can't be expected to know or study every possible topic you might be asked questions about, but that's generally not the aim of these more difficult or esoteric questions. Instead, the interviewer wants to find out how you think and whether you are able to understand the question and reason your way to an answer even if you're unfamiliar with the subject matter.

After all, that's what research is all about: finding answers to questions that no one's studied before. The ability to apply previous reasoning to a new question is particularly important in physics, as we believe the same physical laws should hold anywhere in the Universe. Therefore, a good answer to a such a question would be "I'm not sure, but I would expect from my knowledge of X that Y might happen." And then go into detail as to why. It's also ok to ask for a moment to think before answering.

For what it's worth, PhD interviews are not typically like an exam, and you probably won't be aggressively grilled on your knowledge of a specific topic. More likely, the interviewers will get you to explain any previous research projects you might have done, and discuss your ideas for the future. That's not to say you shouldn't study topics outside your course, if you're interested in them and they're relevant to your intended PhD topic.

  • Yes! I understand. Can you just consider this example? Suppose the interviewer asks, " What would happen if you put a ground state Hydrogen atom in a uniform magnetic field?" Then the student might or might not have read about the Zeeman effect. So if a first student A answered to his current knowledge (as he hasn't read and get into details), and student B answered with an explanation (as he had read the topic). So on which side the interviewer would be biased? Considering that most undergrad doesn't know about this topic. – Young Kindaichi May 27 at 7:20
  • 3
    @YoungKindaichi In my own field and country, no one would ask a question like that in a PhD interview. PhD interviews are to find fits for research labs, not to test acquisition of specific nuggets of knowledge like a course exam. – Bryan Krause May 27 at 13:31
  • 2
    "Saying you don't know the answer to a question is poor interview technique regardless of the situation." - I think this is a rather sweeping claim. If you mean PhD interviews specifically, it may be good to make that explicit. – AppliedAcademic May 27 at 17:08
  • 1
    @AppliedAcademic I don't see why this shouldn't apply for non-PhD interviews. Saying "I don't know" and not giving any elaboration or attempt at an answer is simply not a good thing to do in an interview if you want a good outcome. Relatedly, answering a plain "yes" or "no" to a question is also not a great idea. You should try to sustain the conversation and make the interviewer's job as easy as possible. – astronat May 27 at 20:33
  • 1
    @astronat- Attempting to answer when you're sure you don't have a clue can come across as guessing, bluffing and generally being somewhat deceitful. In such a situation, you'd rather be straightforward and accept a small penalty instead of taking a gamble and possibly annoying the interviewer. – AppliedAcademic May 28 at 14:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.