How to Get Full Marks in CBSE Board Practicals
CBSE Class 12 board practicals: the official 30-mark scheme for Physics, Chemistry and Biology, plus record, viva and project tips to score full marks.
In CBSE Class 12, Physics, Chemistry and Biology each have 30 marks of practicals — 90 marks across PCB. Unlike theory, you know almost exactly what will be assessed. Here is the official scheme for each subject and how to prepare.
Physics (30 marks)
| Component | Marks |
|---|---|
| Two experiments, one from each section | 7 + 7 |
| Practical record (experiments and activities) | 5 |
| One activity from any section | 3 |
| Investigatory project | 3 |
| Viva on experiments, activities and project | 5 |
- Practise with the apparatus — metre bridge, galvanometer, lenses and mirrors, the optical bench.
- Record readings neatly in tables with units, and plot graphs carefully.
- Know the sources of error for each experiment — it helps in the viva.
Chemistry (30 marks)
| Component | Marks |
|---|---|
| Volumetric analysis | 8 |
| Salt analysis | 8 |
| Content-based experiment | 6 |
| Project work | 4 |
| Class record and viva | 4 |
- Salt analysis: learn the systematic scheme for identifying anions and cations.
- Titrations: practise until your readings are consistent.
- Record: write balanced equations for every reaction you perform.
Biology (30 marks)
| Component | Marks |
|---|---|
| One major experiment | 5 |
| One minor experiment | 4 |
| Slide preparation | 5 |
| Spotting | 7 |
| Practical record + viva | 4 |
| Investigatory project and its record + viva | 5 |
- Spotting (7 marks) is the biggest single part — learn to identify each specimen and slide in the syllabus and give its key features.
- Diagrams — large, neat and labelled.
- Slide preparation — practise staining and mounting until it is routine.
Tips That Work in Every Subject
- Complete your record through the year, not in the last week.
- Choose a project topic you can explain — the viva will ask about it.
- Prepare for the viva — know why each step is done, not just how.
- Work methodically on the day — label everything and show calculations.
Prepare theory and practicals together
Super Tutor has chapter summaries, revision notes and practice quizzes for CBSE Class 12 Physics, Chemistry and Biology.
Start freePractical evaluation schemes from the CBSE Senior Secondary Curriculum 2026-27 subject syllabi (cbseacademic.nic.in).
Turn this into exam marks
Super Tutor gives you chapter summaries, revision notes, practice quizzes and an AI doubt solver matched to your board syllabus — so you revise smarter, not longer.
Start freeFrequently Asked Questions
When are CBSE board practicals held?
Schools hold them before the theory exams, usually in January–February. CBSE announces the practical exam window each year in a circular.
Can I score full marks in practicals?
Yes, with preparation. The marks come from clear parts — experiments, the practical record, the project and the viva — so a complete record, practised experiments and a well-prepared viva put full marks within reach.
How long is the Class 12 practical exam?
In Physics, the practical exam is 3 hours. Check your subject's syllabus on cbseacademic.nic.in for the exact duration and scheme.