Practical components and experiments play a crucial role in the science curriculum as they provide hands-on experience to students, fostering better understanding and retention of concepts. The Central Board of Secondary Education (CBSE) for Class 9 includes several practical components and experiments across various science subjects. Let's explore them in detail:

Physics:
1. To determine the focal length of a convex lens using a convex lens formula.
2. To determine the equivalent resistance of two resistors when connected in series and parallel.
3. To study the dependence of potential difference (V) across a resistor on the current (I) passing through it and determine its resistance (R).
4. To verify Ohm's law experimentally.

Chemistry:
1. To separate the components of a mixture using different separation techniques such as filtration, evaporation, and sublimation.
2. To determine the pH of different samples using pH paper or universal indicator.
3. To study the effect of concentration on the rate of reaction between sodium thiosulphate and hydrochloric acid.
4. To prepare a temporary mount of a leaf peel and observe stomata under a microscope.

Biology:
1. To study the stages of mitosis in onion root tip cells.
2. To study the effects of different external factors on the rate of respiration in yeast.
3. To observe and record the external features of various animals and classify them based on their characteristics.
4. To study the structure and function of various plant and animal tissues under a microscope.

These practical components and experiments are designed to develop practical skills, enhance critical thinking, and promote scientific inquiry among students. They also help students understand the application of theoretical concepts in real-life situations. While performing these experiments, students learn to handle apparatus, collect data, analyze results, and draw conclusions.

It is important to note that these practical components and experiments should be performed under the guidance and supervision of a science teacher or instructor to ensure safety and accurate results. Students should also maintain proper records, write detailed observations, and draw relevant diagrams as part of their practical work.

In conclusion, practical components and experiments in CBSE Class 9 science subjects provide a hands-on learning experience, helping students grasp concepts effectively. These experiments are designed to develop scientific skills and foster a deeper understanding of theoretical concepts.