CBSE Class 12 Practical Exam and Viva Tips for Full Marks

Practicals carry 30 marks in subjects like Physics, Chemistry, Biology and Computer Science. They're the easiest marks to secure, if you prepare.

What's usually assessed

• The experiment performed on the day
• The practical file or record
• The project or investigatory project (in most science subjects)
• The viva: oral questions from an internal or external examiner

Practical file

• complete, neat and signed by your teacher
• each experiment with aim, apparatus, theory, procedure, observations, result and precautions
• diagrams in pencil, labelled

On the day

• read the question carefully and write the aim and procedure before starting
• record observations in a proper table with units
• state the result clearly, with precautions and sources of error

Viva: what they ask

• the aim and principle of your experiment
• the "why" behind each step
• precautions and sources of error
• basic definitions and units from the related chapter
• your project: why you chose it and what you found

Answer briefly and honestly. "I'm not sure, but I think…" is better than a confident wrong answer.

Computer Science and IP

Expect to write and run a program (Python or SQL queries), present your practical file and project, and answer viva questions on your code.