How to Prepare for Practical Exams in CBSE Class 12?

Class 12 CBSE students face both theory and practical exams in the board season. While much attention is focused on preparations for written tests, practicals are no less important. In fact, they are worth 20-30% of the total marks in Physics, Chemistry, Biology, Computer Science, and more.

But students often underestimate their importance and take them as a formality. The truth is, practicals are one of the easiest scoring opportunities if you correctly prepare for them. By mastering the theory, conducting some lab work, and being confident in your viva, you can get close to full marks.

In this blog, we will cover subject-specific tips, Class 12 books to study from, and daily smart practices to help students ace their CBSE Class 12 practical exam preparation.

Why are Practical Exams Important?

The practical exams in CBSE Class 12 are not just about mixing chemicals in a test tube and connecting wires in a circuit in a test tube and connecting wires in a circuit. These exams are meant to see if you can translate classroom learning into practical application. In contrast to theory exams, which are entirely based on long written answers, practicals are marked on observation, precision, and understanding of concepts.

They account for 20-30 marks in most science and computer-related subjects and thereby directly impact your final percentage. In fact, a good number of practical marks can actually change your overall performance even if theory marks are variable.

Beyond marks, practical exams build skills you will carry with you: problem-solving, analytical thought, and laboratory techniques. For example, in Chemistry, titration experiments teach precision and patience; in Physics, demonstrating Ohm’s Law deepens your understanding of current and resistance; and in Biology, observing plant tissues under a microscope sharpens observational skills.

Practical examinations are valuable because they:

• Make up a large part of final grades. 

• Test real-world application of concepts.

• Are definite scoring opportunities in the board exams.
  

Structure of CBSE Class 12 Practical Exams

It is important to know what the practical exams look like before planning your preparation. The exact structure may vary slightly based on the subject, but generally, the CBSE Class 12 practical exams consist of the following:

• Experiment / Activity Performance 

• Viva Voce

• Lab Record or Project File 

• Class Performance / Attendance 

These elements all contribute to the practical marks (20-30, varying depending on the subject). So to score highly, you have to prepare all-around, not only perform the experiment, but also know how to explain and present what you have done.

Read More: Is CBSE Class 12 Total Marks 500 or 600?

Subject-Wise Preparation Strategy for CBSE Class 12 Practicals

Each subject in class 12 follows a different system with respect to practicals. Some emphasize experiments, others observation or coding, but all find a need for clear concepts, practice in the lab, and neat presentation. A holistic preparation strategy would thus be to use the NCERT textbooks of Class 12 along with the CBSE question bank and sample question papers for CBSE Class 12. Here’s the subject-specific breakdown:

Physics Practicals

Physics practicals basically put you to the test of applying concepts of motion, electricity, optics, and magnetism to real-world situations. To theoretically prove things such as Ohm’s Law, a convex lens, laws of reflection, etc, and to physically gain confidence in the process requires a great deal of both theory as well as hands-on confidence.

• Use Class 12 NCERT Books PCM: Go through the theory of each experiment from your NCERT Physics book. For instance, the relation between temperature and resistance is clearly laid out in the Ohm’s Law experiment by NCERT.

• Practice in the Lab: Practice working with galvanometers, voltmeters, and lenses. It lessens exam day jitters.

• CBSE Question Banks: Useful for answering viva questions like “What is parallax error and how can you avoid it?”.

• Graphs & Diagrams: Practice plotting graphs and drawing clean circuit diagrams – marks are given for neatness.

• Sample Question Paper CBSE Class 12: Review of the Marking Schemes for understanding how steps, calculations, and precautions are marked.

Chemistry Practicals

Chemical observations, qualitative analysis, and titration accuracy are the focus of chemistry practicals. Because this topic is centered on reactions and color changes, the examiners routinely check for precision and clarity of concepts.

• Start with NCERT Class 12 Book: The NCERT Chemistry book outlines reaction equations, indicators, and procedures for common practicals.

• Master Titrations: Practice acid-base and redox titrations multiple times to avoid endpoint errors.

• Salt Analysis: Memorize cation/anion tests with equations. (E.g., Chloride ion gives a white precipitate with AgNO₃.)

• CBSE Question Banks: Useful for expected viva questions like “Why is a conical flask used instead of a beaker in titration?”

• Lab Record File: Chemistry practicals usually award marks for neat, complete records. Make sure yours is up to date.

Biology Practicals

Biology practicals involve a mixture of observation, identification, and application. Whether from the analysis of permanent slides or from ecological projects, the emphasis is on finding and scientifically explaining the details.

• NCERT Class 12 Biology Book: Vivas and spotting involve a lot of diagrams of animals and plants, so be careful in reviewing the diagrams.

• Slide Identification: Practice spotting permanent slides (onion peel, human cheek cell, dicot/monocot stem) and learn how to justify your identification.

• Experiments: Experiments like potato osmosis or enzyme activity must be rehearsed to avoid careless errors.

• CBSE Question Banks: Ideal for practicing common viva questions such as “Why does plasmolysis occur?”

• Project Work: Ecology or survey-based projects must be neatly written and well-presented.

Computer Science/Informatics Practices(IP) Practicals

The practical exam in the subject of Computer Science deals with programming, writing SQL queries, and executing a project. At this point, logical clarity is more important than writing code.

• Programs & Coding: Practice Python/Java programs by hand; don’t rely on compilers to fix mistakes.

• Databases: Revise SQL queries, joins, and aggregate functions using examples from the sample question paper CBSE Class 12.

• Project File: Ensure your project is well-documented, with proper code comments and explanations.

• Viva Questions: Be ready to explain the logic behind your code or queries—examiners want to see clarity of thought.

• CBSE Question Banks: Great for last-minute revision of commonly asked program-based viva questions.

Best Resources for CBSE Class 12 Practical Preparation

While Class 12 NCERT books PCM and Biology, are your foundation, you also need reliable supporting material for structured practice and last-minute revision. Oswaal provides resources that directly match the CBSE exam pattern and make practical prep much simpler.

Conclusion

CBSE Class 12 practical exams are perceived as difficult, but they can, if you go about it correctly, become your greatest scoring tool. Begin with the Class 12 NCERT textbooks and concepts, go through the experiments as well as the process thoroughly, and then reinforce your preparation with the CBSE question banks, lab manual, and sample question paper from CBSE Class 12.

Keep in mind that practical exams are not looking for perfection; they are looking for clarity, neatness, and confidence. If you practice consistently and prepare intelligently, you can easily get almost full marks in practicals.

CBSE Online Sample Paper and Question Bank for Class 12 Board Exams 2026 

Free CBSE Online Mock Test Sample Papers for Class 12 Board Exams 2026

FAQs on CBSE Class 12 Practical Exams

Q1. What is the weightage of practicals in CBSE Class 12? 

The marks assigned to practical examinations range between 20–30, depending upon the subject.

Q2. Which books are recommended for exam preparation? 

Begin with your Class 12 NCERT books PCM and Biology, and then follow Oswaal CBSE Question Banks and Oswaal Lab Manual Class 12 for in-depth practice.

Q3. Are sample papers helpful for practicals as well? 

Yes. Oswaal Sample Question Papers Class 12 comprise questions in the pattern of the examinations and the marking scheme to understand how the practicals are graded.

Q4. How can I prepare for viva questions? 

Consult the CBSE question banks for common viva questions and review the theory behind each experiment from your NCERT book.