How to Prepare for Viva and Practical Exams: A 3-Day Plan

To prepare for a viva and practical exam, make one short card per experiment covering five things (aim, principle, formula with units, the main source of error, and one "what if" variation), rehearse each card aloud instead of rereading it, and finish your lab record before you touch anything else. For a typical list of eight experiments that is roughly twelve hours of work, which fits into three days of about four hours each without eating into your theory revision.

The usual situation is less tidy than that. Your practical exam is next week, the theory papers follow soon after, the record has three experiments without calculations and two without the instructor's signature, and you performed half of the experiments by copying readings from a lab partner. That is fine. The viva rarely asks anything beyond the experiment list, so it is one of the most predictable assessments of the semester.

What does a viva or practical exam actually test?

A practical exam usually tests three things at once: whether you can carry out a procedure and get sensible readings, whether your record shows the work properly, and whether you understand why the experiment works. The viva is the oral part of that last check.

How these are weighted varies a lot. In some universities the practical is a separate course with its own credits; in others it is a component of a theory subject. The split between performance, record and viva is set by your university, regulation year and department, so check your own scheme of evaluation or ask the lab instructor before deciding where to put your hours.

What varies less is the logic of the viva. Examiners start with an easy question, then move one layer deeper each time you answer well. Your job is to have an answer ready at each layer.

What questions are asked in a viva?

Most viva questions come from six layers, asked roughly in this order: aim, principle, formula, apparatus choice, errors and precautions, and variations. Programming labs swap some of these for logic, edge cases and complexity.

The same layers apply across branches, with different content:

• Physics and electrical labs: graph questions ("what does the slope give you?") and instrument questions (least count, zero error, series or parallel).
• Chemistry labs: indicators, end points, why a reagent is added in excess, safety.
• Programming labs: "walk me through this loop", "what happens with an empty input?", time complexity, choice of data structure.
• Mechanical and civil labs: the material or machine, the standard followed, and how the result is used in practice.

The variation layer is where most students lose marks, because it cannot be memorised word for word. It can be prepared, though, by writing down one variation per experiment and working out its effect from the formula.

How do I make a one-page card for each experiment?

Write one card per experiment with the five core fields, then add the graph shape and your own result. Keep it to one side of a page so you can rehearse it in under five minutes.

Here is an example card for a simple pendulum experiment, the kind found in many first-year physics labs:

A programming card follows the same pattern. For a binary search program: aim (find an element in a sorted array), principle (each comparison halves the remaining range), complexity (O(log n) comparisons in the worst case), main error (off-by-one mistakes when updating the low and high indices), variation ("what if the array is unsorted?" The algorithm gives wrong answers, so you must sort first or use linear search).

Two rules make the cards useful. Write them from your record and lab manual, not from a generic viva question list, because examiners ask about the setup you actually used. And write the "my result" line honestly, because "why is your value off?" is one of the most common questions and the answer is your error field.

How long does it take to prepare for a viva?

As a starting estimate, about an hour to seventy-five minutes per experiment: forty to fifty minutes to build the card, then fifteen to twenty minutes to say it aloud and fix the gaps. Add two to three hours for the record and calculation practice.

Worked for a list of eight experiments:

• Cards: 8 × 50 minutes = about 6.5 hours
• Spoken rehearsal, first round: 8 × 15 minutes = 2 hours
• Record completion and calculation practice: about 2.5 hours
• Shuffled drill on the last day: about 1 hour
• Total: roughly 12 hours

Treat these as figures to calibrate, not rates you must hit. If your first two cards take ninety minutes each, add a fourth day or write lighter cards for the simpler experiments.

Twelve hours is also a ceiling worth respecting. A student who spends five days on the viva often pays for it in the theory paper that follows. If you want the wider picture of how the practical sits in your exam block, the semester exam plan guide shows how to lay out a full datesheet.

What does a 3-day plan for eight experiments look like?

Day one fixes the record and builds the first four cards, day two builds the rest and starts speaking them aloud, and day three is a shuffled drill with procedure and calculation practice. Each day ends with recall, not rereading.

The spoken round is the part students skip, and it matters most. Saying an answer aloud without looking forces retrieval, and retrieval practice has strong evidence behind it: Roediger and Karpicke (2006) found that testing yourself produced better delayed retention than restudying the same material. A viva is a spoken test, so practising it as one is doubly useful. The guide to active recall versus rereading explains how to turn notes into prompts if you want to go further.

If you only have one day, compress it: one hour on the record, five minutes per card for a bare-bones version of all eight (aim, formula, one error), then a shuffled drill in the evening. You lose the variation layer for most experiments, but you keep the questions examiners ask first.

How do I prepare for the practical part, not just the viva?

Practise the procedure in writing and the calculation with real numbers. The viva tests whether you understand the experiment; the practical tests whether you can do it within the slot without losing your way.

For each experiment, write the steps from memory in order, then check them against the manual. Sketch the setup or circuit diagram without looking. Draw the empty observation table with correct column headings and units, because a well-laid-out table is quick marks and a messy one costs time on the day. Then take the readings from your record and do the full calculation once, timing yourself.

That run also tells you the range a sensible result falls in, so a value ten times too large on the day prompts a unit check before you write the result.

For programming practicals, type each program from scratch once without looking, then test an edge case: empty input, one element, the largest value. If you are asked to modify a program on the day, knowing why each line is there matters more than recalling it exactly.

What should be in my lab record before the exam?

Your record should have a complete entry for every experiment on the list, with the instructor's signature where your lab requires one. Finish it first, because it is the one part of the practical you can fully control in advance.

Signatures get harder to collect in the last two days, when every student is chasing the same instructor, so sort out missing ones on day one.

How do I answer a viva question when I don't know the answer?

Pause, restate the question, say what you know that is closest to it, and reason aloud from the principle. If that still fails, say clearly that you are not sure. A confident wrong answer usually leads to harder follow-ups; honest reasoning often earns partial credit.

A short script helps because it stops panic from making the decision for you:

1. Pause for two or three seconds. Silence feels long to you and normal to the examiner.
2. Restate it. "You're asking why the reading drops when the resistance goes up?" Sometimes this alone reveals the answer, and it confirms you have understood the question.
3. Anchor to what you know. "I know the current depends on the voltage and resistance from Ohm's law, so..."
4. Reason one step. Work from the formula on your card to a likely answer, and say it as reasoning rather than fact.
5. Close honestly if stuck. "I'm not sure of that one. I'd check it in the manual." Then stop talking.

If your mind goes completely blank, the guide to what to do when your mind goes blank in an exam has a short reset routine that works in an oral exam as well as a written one.

Two habits help in the room. Give a short, direct first answer and let the examiner ask for more, because long answers to easy questions use up the slot. And explain in your own words, using a quick sketch on rough paper when a diagram is clearer than a sentence. The Feynman technique is good practice for exactly that kind of plain explanation.

How do I fit viva preparation into the rest of my exams?

Time-box it to about three days and protect your theory revision on either side. Practicals often come before the theory papers in an exam block, and the danger is that the practical swallows a week you needed for something else.

If you already have a running plan for internals, treat the practical like any other assessment with a fixed date and a fixed budget. The guide to internal assessment and sessional exam planning covers that rhythm. If two practicals fall in the same week, prepare the earlier one first but rotate in a short daily rehearsal of the later one's cards, so it is not starting cold.

How can I run this in MyStudyPlanner?

MyStudyPlanner has no viva-specific feature, but you can put the practicals into the same plan as your theory papers. There are no semester templates, so you choose "Other", add your theory courses as subjects, and add a "Practicals" paper with a subject per lab where Lectures equals the number of experiments and Priority reflects how much the lab is worth to you. Each experiment becomes a dated task named by paper, subject and lecture number, which you can rename to the experiment's title by hand. Short revision tasks are added one, three, seven and fourteen days later if a day has room and the date falls before your target completion date, so in a three-day window only the next-day revisions will appear. The free plan allows one study plan in total, which is another reason to keep practicals inside your semester plan rather than in a separate one.

What if the practical goes wrong on the day?

Tell the examiner early, show your method, and explain the likely cause using the error field from your card. A wrong reading handled well is usually worth more than a right one you cannot explain.

Common problems and what to do:

• Readings look wrong. Recheck units and zero error first, then repeat one reading. If time is short, record what you got and note the suspected error source in the result.
• Apparatus fault. Report it straight away rather than ten minutes before the end; examiners can only help if they know.
• Program will not compile. Read the first error message only, fix it, and recompile. Chasing every error at once wastes the slot.
• You get an experiment you prepared least. Use the card-level structure anyway: aim, principle, formula, procedure. Most marks come from a correct method, not perfect numbers.

If it goes badly overall, note what went wrong while it is fresh, then move on. Dwelling on it costs revision time you still control.

Frequently Asked Questions

How do I prepare for a viva in one day?

Spend the first hour finishing and checking your lab record, then make a short card for each experiment with its aim, principle, formula, main error source and one variation. Say each card aloud from memory rather than rereading it. Leave the last hour for a shuffled drill where you or a friend pick experiments at random. One day will not make you expert, but it covers the questions examiners ask most.

What questions are asked in a practical viva?

Most viva questions fall into a few predictable layers: the aim of the experiment, the principle behind it, the formula and what each symbol means, why a particular instrument or step is used, the sources of error and precautions, and what would change if one condition changed. Programming labs add questions about logic, edge cases and time complexity. Prepare all six layers for every experiment.

How do I answer a viva question when I don't know the answer?

Pause, restate the question to check you have understood it, then say what you do know that is closest to it and reason aloud from the principle. If you still cannot reach an answer, say plainly that you are not sure. Examiners usually respond better to honest reasoning than to a confident wrong answer, which tends to invite harder follow-up questions.

How many experiments should I prepare for a practical exam?

Prepare every experiment on the list, because in many labs the experiment is allotted on the day, sometimes by lot, so you cannot predict which one you will perform. You do not need equal depth for all of them. Give the full procedure walkthrough to the longest or most calculation-heavy experiments and a card-level review to the simpler ones.

Does the lab record matter in a practical exam?

In many universities it does, because the record is often checked or marked during the practical exam and some labs will not let you sit without a complete, signed record. How much it carries varies by university and course, so check your own scheme. Either way, an incomplete record is the easiest problem to fix and should be finished before anything else.

How long should I spend preparing for a viva?

As a starting estimate, budget about an hour to seventy-five minutes per experiment for the card and a spoken rehearsal, plus two or three hours to finish the record and practise calculations. For eight experiments that comes to roughly twelve hours, which fits into three days without taking over your theory revision. Calibrate the figure against how long your first two cards actually take.

Your next step

Open your lab record today and spend forty-five minutes on the audit table above: list every experiment, mark what is missing (calculations, result, diagram, signature), and fix the two easiest gaps before you stop. Then write the card for experiment one and say it aloud once without looking. That single card tells you how long the other seven will take.