Practical examinations have a small syllabus, a published format and very few surprises. They are also the component students prepare for last, if at all — which is why a meaningful number of otherwise strong students lose marks here.

Why practicals are the easiest marks available

The list of experiments is known in advance
The procedure does not change year to year
The viva questions come from a narrow, predictable pool
The journal is prepared over months, not on the day

Nothing about this is difficult. It is only ever neglected.

The journal

Written up as you go, not reconstructed in a panic the week before. A journal completed in three days looks exactly like a journal completed in three days, and examiners have seen many.

Aim, apparatus, diagram, procedure, observations, calculation, result, precautions. The precautions section is the most commonly skipped and the most commonly asked about.

The viva

Examiners ask about what you did, not about the whole syllabus. For each experiment, be able to answer:

What is the aim, in one sentence?
Which principle does it rest on?
Why this apparatus, and what would go wrong with a substitute?
What are the main sources of error?
What would happen if you changed one variable?

Five questions per experiment. For a syllabus of a dozen experiments, that is an evening's preparation for a substantial share of marks.

On the day

Read the assigned experiment fully before touching anything.
Draw the diagram first — it settles the procedure in your head.
Record observations as you take them, not from memory afterwards.
Show the calculation with units at every stage.
If a reading looks wrong, say so and explain why rather than quietly adjusting it. Examiners respect that; they notice the alternative.

For students also preparing for entrance exams

Do not skip practicals on the grounds that JEE and NEET do not test them. Board marks matter for admission routes, and the understanding gained from actually performing an experiment tends to make the theory stick.

Frequently asked

How much do practicals carry?

Enough to move a final percentage noticeably. Check the current scheme for your board and year.

What if I damage equipment?

Say so immediately. It is not penalised; concealing it is.

Can I prepare the viva from the journal alone?

Mostly, if the journal was written properly. If it was copied, you will find out during the viva.

Why these marks get thrown away

Because they are available. A student who is anxious about the theory paper spends their anxiety there, and the practical component — which is closer to guaranteed than anything else in the year — gets whatever attention is left the night before.

It is worth seeing this clearly: these are the most reliably obtainable marks in Class 12. They do not depend on which questions come up. Losing them to a journal completed in a hurry is the cheapest mistake available, and it is entirely avoidable.

The journal, kept properly, is most of the work

Write it up the same week you do the experiment, while you still remember what actually happened. A journal reconstructed in March from a friend's copy shows, and it is a poor foundation for a viva that will be asked about your own readings.

Aim, apparatus, procedure, observations, calculation, result, and a line on sources of error. The last one is small and regularly skipped.
Record what you observed, including the reading that did not fit. An examiner who sees only clean data usually asks why.
Keep units in the table headings, not written beside every number.

Preparing for the viva in an hour

The viva is not a memory test on the whole syllabus. It is nearly always about the experiments in your own journal, and it is answerable in an hour of preparation.

For each experiment, be ready with: what you were measuring and why, which piece of apparatus does the important work, what would happen if a specified thing changed, and where the error in your result most likely came from. That last question is asked constantly and answered badly.

If something goes wrong during the practical, say so and describe it rather than adjusting the numbers. Examiners deal with unfamiliar apparatus and imperfect readings every year; a student who can explain what went wrong usually does better than one whose results are suspiciously tidy.

Practical work and the viva happen at your junior college, so this part is in your own hands. Our 11th & 12th Science coaching in Nashik concentrates on the theory papers and entrance preparation — which is exactly why the habits above are worth building from the first practical.

Practicals and Viva: The Easiest Marks Students Throw Away