Viva Questions for Physics

Physics vivas demand a strong command of both the theoretical foundations and experimental or computational methods behind your research. Examiners will probe your understanding of the physics at play, your ability to derive and interpret results, and your grasp of uncertainties and error analysis. Whether your work is experimental, theoretical, or computational, you'll be expected to show rigour in your reasoning and clarity in your explanations.

Physics vivas often feel more like a scientific discussion than a formal examination. Your examiners – usually active researchers in related areas – will engage with your work as peers. They may ask you to sketch a derivation, walk through an order-of-magnitude estimate, or explain a concept from first principles. The tone is typically collegial, but the intellectual demands are high.

Questions about your research

Physics examiners want to see that you understand your experiment or calculation at every level – from the high-level motivation down to the practical details of how you handled systematic effects or numerical convergence. They'll ask about your error budget, your calibration procedures, and the assumptions embedded in your analysis. If your work is theoretical, expect to be asked to reproduce key steps in your derivations or to justify approximations you've made.

• Can you give a concise summary of your thesis and its principal results?
• What is the physical motivation behind your research question – why should we care about this?
• How did you design your experiment or set up your simulation, and what were the key design choices?
• Walk us through your error analysis – what are the dominant sources of uncertainty, and how did you quantify them?
• How did you calibrate your equipment or validate your computational model against known results?
• What approximations did you make, and how do they affect the reliability of your conclusions?
• Were there any systematic effects you had to account for, and how did you do so?
• How does your data compare with existing theoretical predictions or previous measurements?
• What would you need to do to improve the precision of your measurements by an order of magnitude?
• Can you explain the key equations or derivations underlying your work without referring to your thesis?
• How did you handle data quality issues – cuts, outliers, or detector artefacts?
• What software or computational tools did you develop or adapt for your analysis?

Questions about theory and literature

In physics, the relationship between theory and experiment is central. Examiners will want to know how your work connects to the theoretical framework of your subfield, whether your results confirm, challenge, or extend existing models, and how well you understand the assumptions that underpin the theories you've used. If your work is purely theoretical, expect questions about how your predictions could be tested experimentally.

• How does your work fit within the current theoretical framework of your subfield?
• Are there competing models or interpretations that could explain your observations?
• What are the key assumptions in the theory you're using, and how well do they hold in your regime?
• Which papers or experimental results motivated your specific approach?
• How has your subfield evolved during the period of your PhD, and has that changed the significance of your results?
• If your theoretical predictions don't match your data, what does that tell us – is it the theory, the experiment, or something else?
• How does your work relate to the broader open questions in your area of physics?

Questions about contribution and impact

Physics examiners will want to understand what your work adds to the field – whether that's a new measurement, a new theoretical prediction, a methodological advance, or a constraint on an existing model. They'll also be interested in where your work leads next. Be precise about what you've achieved and honest about what remains to be done.

• What is the most significant result in your thesis, and what makes it original?
• How do your results advance the current state of knowledge in your area?
• Are there technological or practical applications of your findings, or is this primarily fundamental research?
• What would be the next experiment or calculation to build on your work?
• How might your results influence the direction of research in your subfield over the next five to ten years?
• If your result is confirmed by future experiments, what are the broader implications for physics?

Tough follow-ups your examiners might ask

Physics examiners will stress-test your conclusions. They'll ask about the robustness of your error estimates, push you on approximations, and explore whether your results could be artefacts of your measurement technique or analysis pipeline. The best preparation is to have thought carefully about what could be wrong with your own work before your examiners point it out.

• You've quoted this uncertainty – can you justify that estimate in more detail?
• How would your conclusions change if this approximation broke down in the regime you're studying?
• Could this result be an artefact of your detector response or analysis pipeline?
• Can you derive this result from first principles on the whiteboard?
• If someone gave you ten times the beam time, computing power, or funding, what would you do with it?
• What is the single biggest weakness in your analysis, and how would you address it?
• How would your results change if you used a different fitting method or prior?

Ready to practise? These are the kinds of questions your examiners will ask – but in a real viva, they won't stop at the first answer. They'll follow up, probe deeper, and test how well you can think on your feet. Try VivaCoach to practise with AI-powered follow-up questions tailored to your thesis.

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