CBSE Class 10 Science Practicals 2027: Complete Guide with Tips to Score Full Marks

The CBSE Class 10 Science practical exam carries 20 marks out of the total 100. That is one-fifth of your Science grade decided before you even sit for the theory paper. Yet many students treat practicals as an afterthought, losing easy marks they could have scored with minimal preparation.

This guide covers everything about the 2027 CBSE Class 10 Science practical exam: the experiments, the viva, the internal assessment, and exactly how to maximize your score.

Practical Exam Structure

The 20 marks for Science practicals are divided as:

The practical exam is conducted by your own school, usually in January-February before the board theory exam in March.

List of Class 10 Science Experiments

The CBSE prescribed list includes experiments from Physics, Chemistry, and Biology:

Physics Experiments

1. Finding the focal length of a concave mirror
2. Finding the focal length of a convex lens
3. Tracing the path of a ray of light through a glass slab
4. Tracing the path of a ray through a glass prism
5. Finding the image distance for varying object distances in case of a convex lens
6. Determining the equivalent resistance of resistors in series
7. Determining the equivalent resistance of resistors in parallel

Chemistry Experiments

1. pH of different solutions using pH paper or universal indicator
2. Properties of acids and bases (reaction with metals, carbonates, etc.)
3. Single displacement reaction (iron nails in copper sulphate solution)
4. Double displacement reaction (barium chloride + sodium sulphate)
5. Distinguishing between acidic, basic, and neutral solutions

Biology Experiments

1. Preparing a temporary mount of a leaf peel to show stomata
2. Observation of binary fission in Amoeba and budding in Yeast (from slides)
3. Identification of different parts of an embryo of a dicot seed
4. Homology and analogy in plants and animals (from charts/models)

How to Score Full Marks in the Lab Exam

Before the Exam

1. Read the procedure for every experiment at least twice
2. Practice drawing diagrams: circuit diagrams for Physics, apparatus setup for Chemistry, biological diagrams for Biology
3. Learn the observation tables: what to measure, what columns to draw, what units to use
4. Prepare a list of common viva questions for each experiment (see below)

During the Exam

1. Listen to the examiner's instructions carefully. They will tell you which 2 experiments to perform
2. Set up the apparatus neatly before starting
3. Take at least 3-5 readings for Physics experiments (not just one)
4. Record observations in a proper table format with correct units
5. Calculate results accurately. Show the formula and working
6. Draw diagrams with pencil first, then label clearly

Common Viva Questions

The examiner will ask 4-5 questions during or after your experiments. Most common:

For focal length experiments: "What is the difference between real and virtual image?" "What happens if the object is at the focus?"

For resistance experiments: "What is Ohm's law?" "Why does resistance increase in series?"

For pH experiments: "What is the pH of pure water?" "Name a natural indicator."

For biology: "What is the function of stomata?" "What is binary fission?"

Prepare short, confident answers. The examiner is not trying to fail you. They want to see that you understand what you did.

Internal Assessment (5 Marks)

These 5 marks come from:

• Periodic tests conducted throughout the year
• Notebook/portfolio evaluation
• Subject enrichment activities (projects, models)

The key: maintain your practical notebook throughout the year. Write each experiment neatly after performing it. Do not leave everything for the last month.

Practical Record (Notebook)

Your practical notebook is evaluated during the exam. It should contain:

• All experiments listed in the syllabus
• Each experiment with: Aim, Materials Required, Procedure, Observation Table, Result, Precautions
• Diagrams where applicable
• Neat handwriting and clean pages

Use a ruler for drawing tables. Use pencil for diagrams. Leave margins. These presentation details matter for scoring.

Last-Minute Preparation Checklist

One week before the practical exam:

• Re-read all experiment procedures
• Practice drawing 3 Physics diagrams, 2 Chemistry setups, 2 Biology diagrams
• Review common viva questions and answers
• Check that your practical notebook is complete and neat
• Carry all required stationery: pen, pencil, eraser, ruler, calculator (if allowed)

How Padhaao Helps with Practicals

While Padhaao focuses on theory chapter content, many of the practical concepts are explained within the relevant chapters. For example:

• Light chapter covers ray diagrams and lens concepts
• Electricity chapter covers Ohm's law and resistance
• Life Processes chapter covers stomata and plant biology

Using the Lecture mode to revise these chapters before the practical exam reinforces both theory and practical understanding. The Key Points mode gives you a quick review of formulas and definitions that commonly appear in viva questions.

The Bottom Line

Science practicals are the easiest 20 marks in your Class 10 exams. With one week of focused preparation, complete practical records, and confidence during the viva, scoring 18-20 out of 20 is very achievable. Do not leave these marks on the table.