Laboratory Records and Vivas: Easy Marks You Are Losing

Practical examinations and records carry real weight in the semester, and unlike theory papers they are almost entirely within your control. They are also where students are most careless, because laboratory sessions feel less serious than lectures.

Why the record matters more than it seems

A laboratory record is assessed on whether it shows you understood the experiment, not on neatness alone. An examiner reading a record can tell within a page whether the student ran the experiment or copied the numbers. Readings that are impossibly consistent are the usual giveaway.

Write up the same week. A record completed the night before submission from someone else's numbers teaches nothing and reads exactly as what it is.

What a viva actually tests

Whether you understood what you did and why. The questions cluster in predictable places: what the experiment demonstrates, why the apparatus is arranged that way, what the sources of error are, what would happen if a parameter changed, and how the result compares with theory.

That last one is the most common and the least prepared. Know your theoretical value and be able to explain the difference.

Preparing in ten minutes

1. Before the session, read what the experiment is meant to demonstrate. Ten minutes is enough.
2. During, note anything odd as it happens. Odd things are what get asked about.
3. After, write the record while the session is fresh.
4. Before the viva, for each experiment know the principle, the main source of error and the theoretical comparison.

On errors

A result that differs from theory is not a failure, and saying so confidently with a plausible explanation scores better than a suspiciously perfect number you cannot account for. Examiners are looking for engineering judgement, and judgement includes knowing when a measurement is off and why.