Preparing for the CBSE Class 10 Science Viva Questions with Answers 2025 can seem daunting, but with the right approach, it can become a great opportunity to showcase your knowledge. The Science practical exam is an important part of your overall assessment, focusing on both theoretical understanding and hands-on skills.
In the viva, students will be asked questions related to their practical experiments, class records, and concepts studied throughout the year. For the 2025 session, the viva holds 4 marks out of the total 30 marks for the practical exam.
The CBSE Class 10 Science Viva is an essential part of the practical exam that helps assess students' understanding of scientific concepts and their ability to apply them. The viva includes questions from various chapters such as Physics, Chemistry, and Biology, where students are asked about the experiments they conduct and the theory behind them. Preparing for science viva questions class 10 can significantly boost students' confidence and performance. By practicing science class 10 viva questions, students can improve their conceptual clarity and presentation skills, which in turn, can help them score better marks in their class 10 science viva questions.
This article offers CBSE Class 10 Science Viva Questions with Answers 2025, designed to help students prepare effectively for their practical exams. It includes key questions and answers that are crucial for acing the viva and gaining confidence while interacting with examiners.
Q1. What is Ohm's law?
Answer: Ohm's law states that the current passing through a conductor is directly proportional to the voltage across it, provided the temperature remains constant. Mathematically, .
2. Explain the working principle of an electric motor?
Answer: An electric motor operates based on the principle that a conductor carrying an electric current, when placed within a magnetic field, experiences a force. This force causes the conductor to move, which is the fundamental mechanism behind the motor's motion.
3. How do series circuits differ from parallel circuits?
Answer: Series Circuit: Components are connected end-to-end, so the current is the same through all components.
Parallel Circuit: Components are connected across common points, so the voltage across each component is the same.
4. What is the law of reflection?
Answer: The law of reflection states that the angle of incidence is equal to the angle of reflection, both measured from the normal to the reflecting surface.
5. How do conductors and insulators differ from each other?
Answer: Conductors are materials that allow electricity to flow through them (e.g., metals), while insulators are materials that do not allow electricity to flow through them (e.g., rubber, wood).
6. How does a convex lens create an image?
Answer: A convex lens bends incoming parallel light rays toward a single point called the focal point. Depending on the object's distance from the lens, the image can be either real or virtual.
7. What is the use of a fuse in an electric circuit?
Answer: A fuse is a safety device that protects an electrical circuit from excessive current. It melts when the current exceeds a certain limit, preventing damage to the circuit.
8. What are the factors affecting the resistance of a conductor?
Answer: The resistance of a conductor is affected by the material, length, cross-sectional area, and temperature of the conductor.
9. Explain principle of conservation of energy?
Answer: The principle of conservation of energy states that energy cannot be created or destroyed; it can only be transformed from one form to another. The total energy in a closed system remains constant.
10. Explain the difference between reflection and refraction of light.
Reflection is the bouncing back of light when it strikes a surface, while refraction is the bending of light as it passes from one medium to another due to a change in speed. Reflection occurs at interfaces like mirrors, whereas refraction occurs at boundaries between different media like air and water.
11. Explain what a convex lens does to light rays.
A convex lens converges light rays that are parallel to its principal axis toward a single point known as the focal point. This property allows convex lenses to magnify images and focus light for applications such as cameras and eyeglasses.
12. What is gravitational potential energy?
Gravitational potential energy refers to the energy an object has because of its height or position in a gravitational field. It is determined by the object's mass, the height from the ground, and the strength of the gravitational pull, and can be calculated using the formula
PE = mgh,
where
PE is potential energy,
m is mass,
g is acceleration due to gravity, and
h is height above ground level.
1. What distinguishes a physical change from a chemical change?
Answer: A physical change involves a modification in the state or appearance of a substance without affecting its chemical identity. For example, melting ice into water is a physical change. In contrast, a chemical change leads to the creation of one or more new substances with distinct properties, such as when iron rusts and forms iron oxide.
2.What is the principle of conservation of mass?
Answer: The principle of conservation of mass asserts that during a chemical reaction, the total mass remains constant; it cannot be created or eliminated. This means that the mass of the reactants before the reaction is equal to the mass of the products formed afterward.
3. Explain the process of filtration.
Answer: Filtration is a method of separating solid particles from a liquid or gas using a filter medium, such as filter paper, which allows only the liquid to pass through.
4. What is an acid-base indicator?
Answer: An acid-base indicator is a substance that changes color in response to changes in pH.
5. What are the characteristics of ionic compounds?
Answer: Ionic compounds are usually hard, brittle, have high melting and boiling points, and conduct electricity when dissolved in water or melted.
6. What is the difference between an endothermic and an exothermic reaction?
Answer: Endothermic Reaction: Absorbs energy from the surroundings (e.g., photosynthesis).
Exothermic Reaction: Releases energy to the surroundings (e.g., combustion).
7. Explain the process of rusting of iron.
Answer: Rusting is the slow chemical reaction of iron with oxygen and water, leading to the formation of iron oxide (rust). It is an example of an oxidation reaction.
8. What is the significance of the pH scale?
Answer: The pH scale measures the acidity or alkalinity of a solution. A pH less than 7 is acidic, 7 is neutral, and greater than 7 is alkaline.
9. Define the term ‘oxidation’ in terms of electron loss.
Answer: Oxidation is the process where an atom, ion, or molecule loses electrons, resulting in an increase in its oxidation state.
10. What is a covalent bond?
Answer: A covalent bond is formed when two atoms share one or more pairs of electrons to achieve a stable electron configuration.
11. What is meant by the term ‘molar mass’?
Answer: Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is numerically equivalent to the substance’s atomic or molecular mass.
12. Explain the concept of an alloy.
Answer: An alloy is a mixture of two or more metals, or a metal and a non-metal, to improve its properties, such as strength, durability, or resistance to corrosion (e.g., steel is an alloy of iron and carbon).
13. What is an acid-base indicator? Give an example.
An acid-base indicator is a substance that changes color in response to changes in pH, indicating whether a solution is acidic or basic. An example is litmus, which turns red in acidic solutions and blue in basic solutions.
14. What is rusting, and how can it be prevented?
Rusting is the corrosion of iron due to its reaction with oxygen and moisture, forming iron oxide (rust). It can be prevented by applying protective coatings (like paint), using stainless steel, or galvanizing (coating with zinc).
15. What do you understand by the term 'reactivity series'?
The reactivity series is a hierarchical arrangement of metals based on their reactivity levels, organized from the most reactive to the least reactive. This series helps predict how metals will react with other substances, such as acids and water.
1. What is the function of the mitochondria in a cell?
Answer: Mitochondria are often referred to as the cell's powerhouses because they generate energy in the form of ATP (adenosine triphosphate) through the process of cellular respiration.
2. Describe the process of photosynthesis.
Answer: Photosynthesis is the process by which plants convert light energy into chemical energy, using chlorophyll to convert carbon dioxide and water into glucose and oxygen.
3. What is the function of the large intestine in digestion?
Answer: The large intestine absorbs water and salts from the undigested food and forms feces for elimination from the body.
4. What is the process of fertilization in humans?
Answer: Fertilization in humans occurs when a sperm cell from the male fuses with an egg cell from the female to form a zygote, which develops into an embryo.
5. What are enzymes and how do they function?
Answer: Enzymes are proteins that act as catalysts in biochemical reactions, speeding up processes by lowering the activation energy needed for reactions to occur. Each enzyme is specific to a particular substrate and binds to it at an active site. This interaction forms an enzyme-substrate complex, allowing the conversion of substrates into products. Enzymes remain unchanged after the reaction, enabling them to be reused in multiple reactions. They are essential for various biological functions, including digestion and metabolism.
6. What is the structure of a DNA molecule?
Answer: DNA is a double helix structure made up of two strands of nucleotides, each consisting of a sugar, phosphate group, and a nitrogenous base (adenine, thymine, cytosine, and guanine).
7. Explain the process of respiration in plants.
Answer: Respiration in plants involves the breakdown of glucose into carbon dioxide and water to release energy, which is used for growth and development.
8. What is the difference between mitosis and meiosis?
Answer: Mitosis: Results in two identical daughter cells, occurs in somatic cells, and involves one division.
Meiosis: Results in four non-identical daughter cells, occurs in gametes, and involves two divisions.
9. How do vaccines help in immunity?
Answer: Vaccines contain weakened or inactive parts of pathogens that stimulate the body’s immune system to produce antibodies, providing immunity without causing disease.
10. What is the role of the nephron in the human excretory system?
Answer: The nephron filters blood in the kidneys, removing waste products and excess substances, which are then excreted as urine.
12. Explain the process of respiration in living organisms?
Answer: Respiration is a biochemical process through which living organisms transform glucose and oxygen into energy, along with carbon dioxide and water. This process can take place in two forms: aerobic respiration, which requires oxygen, and anaerobic respiration, which occurs in the absence of oxygen. Aerobic respiration yields significantly more energy than anaerobic respiration, making it the more efficient pathway for energy production.
The practical examination for CBSE Class 10 Science plays a crucial role in assessing students' understanding of experimental techniques and hands-on skills. The marks for the practical exam are divided into different components that test both the theoretical knowledge and the application of concepts in real-life experiments.
Here is the marks distribution for the practical exam:
Here are some points given that can help students in preparing for the CBSE Class 10 Science viva exam:
Questions often include inquiries about the objectives of experiments, observations made during the experiment, the significance of results, and explanations of underlying scientific principles.
To pass the viva exam, students should thoroughly understand the experiments conducted, be able to explain their observations clearly, and practice answering common questions related to their practical work.
Yes, practical skills are assessed during the viva voce. Students may be asked to demonstrate techniques or explain procedures used in experiments, highlighting their hands-on abilities.
Yes, performing well in the viva is important as it contributes to the overall assessment in practical subjects and can significantly impact final grades.
Useful resources include lab manuals, online tutorials, study guides, past exam papers, and discussions with teachers or peers who have experience with the practical components of the curriculum.