The CBSE Class 10 Science Sample Paper 2023-24 is designed according to the latest competency-based exam pattern issued by the board. It includes a balanced mix of objective, short answer, long answer, and case-based questions to assess conceptual understanding and application skills.
This sample paper helps students become familiar with the structure, marking scheme, and difficulty level expected in the actual board exam. On this page, you will find all 24 questions of the official sample paper along with accurate, easy-to-understand solutions in plain text format—making it perfect for revision and exam practice.
CBSE Class 10 Science Sample Paper 2023-24 – Solved
SECTION A (1 mark each)
1. Test tube containing solution of sodium sulphate. Test tube containing solution of barium chloride. Identify the product which represents the solid state in the above reaction.
The solid state product is Barium sulphate. This is a double displacement reaction between sodium sulphate (Na2SO4) and barium chloride (BaCl2), which produces sodium chloride (NaCl) and barium sulphate (BaSO4). Barium sulphate is an insoluble salt that precipitates as a white solid.
2. The colour of the solution observed after 30 minutes of placing zinc metal to copper sulphate solution is
The correct answer is Colourless. Zinc is more reactive than copper, so it displaces copper from the copper sulphate solution. The initial blue color, due to copper ions, fades as they are replaced by colorless zinc ions to form zinc sulphate.
3. Mild non-corrosive basic salt is
A mild, non-corrosive basic salt is Sodium bicarbonate (NaHCO3). This is because it is a salt formed from a strong base (sodium hydroxide) and a weak acid (carbonic acid), making its solution mildly basic.
4. On adding dilute sulphuric acid to a test tube containing a metal ‘X’, a colourless gas is produced when a burning matchstick is brought near it. Which of the following correctly represents metal ‘X’?
The metal ‘X’ is Sodium. This is because reactive metals like sodium react with dilute acids to produce hydrogen gas, which burns with a ‘pop’ sound.
5. Which one of the following correctly represents Sodium oxide?
The correct representation of Sodium oxide is 2Na+ [O]2−. This ionic compound is formed when each of the two sodium atoms donates one electron to the oxygen atom.
6. An element with atomic number will form a basic oxide.
An element with atomic number 11 (2,8,1) will form a basic oxide. This is because it is Sodium, a metal, and metals generally form basic oxides.
7. An element ‘M’ has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of ‘M’ is:
The atomic number of element ‘M’ is 14. The 2nd shell holds 8 electrons, so the 3rd shell holds 4 electrons (50% of 8). The total number of electrons is 2+8+4=14.
8. Generally food is broken and absorbed within the body of organisms. In which of the following organisms is it done outside the body?
The correct answer is Mushroom. Mushrooms are fungi that secrete digestive enzymes onto their food source to break it down externally before absorbing the nutrients.
9. Receptors are usually located in sense organs. Gustatory receptors are present in
Gustatory receptors are present in the tongue. They are the specialized sensory receptors responsible for the sense of taste.
10. A farmer wants to grow banana plants genetically similar enough to the plants already available in his field. Which one of the following methods would you suggest for this purpose?
The suggested method is Vegetative propagation. This is an asexual reproductive process that produces genetically identical offspring, which is what the farmer wants.
11. Height of a plant is regulated by:
The height of a plant is regulated by Growth hormones under the influence of the enzymes coded by a gene. Genes provide the instructions for producing enzymes, which then control the production and action of growth hormones.
12. A sportsman, after a long break of his routine exercise, suffered muscular cramps during a heavy exercise session. This happened due to:
This occurred due to a lack of oxygen and formation of lactic acid. During heavy exercise, the muscles switch to anaerobic respiration, producing lactic acid as a byproduct, which causes cramps.
13. An object is placed in front of a convex mirror. Its image is formed:
The image is always formed behind the mirror and its position varies according to the object distance. The image is virtual, erect, and diminished.
14. When light enters the atmosphere it strikes on extremely fine particles, which deflect the rays of light in all possible directions, This is due to –
This phenomenon is due to scattering of light. This process is why the sky appears blue.
15. In 1987, an agreement was formulated by the United Nations Environment Programme (UNEP) to freeze the production of “X” to prevent depletion of “Y”. “X” and “Y” respectively referred here are:
The correct answer is CFCs; Ozone. The Montreal Protocol was an agreement to phase out the production of chlorofluorocarbons (CFCs) to protect the ozone layer.
16. Which of the following features relates to biodegradable substances?
A key feature of biodegradable substances is that they are broken down by biological processes. This decomposition is carried out by microorganisms.
17. Assertion: Rusting of Iron is endothermic in nature. Reason: As the reaction is slow, the release of heat is barely evident.
The correct option is A is false but R is true. Rusting is an exothermic reaction, not endothermic. However, the reason is correct in that the slow nature of the reaction makes the heat release difficult to notice.
18. Assertion: Probability of survival of an organism produced through sexual reproduction is more than that of organism produced through asexual mode. Reason: Variations provide advantages to individuals for survival.
The correct option is Both A and R are true, and R is the correct explanation of A. Sexual reproduction creates genetic variations, which can provide an advantage for survival, especially in a changing environment.
19. Assertion: A compass needle is placed near a current carrying wire. The deflection of the compass needle decreases when the magnitude of the current in the wire is increased. Reason: The strength of a magnetic field at a point near the conductor increases on increasing the current.
The correct option is A is false but R is true. The deflection of the compass needle should increase, not decrease, when the current and thus the magnetic field strength increases. The reason is a true statement.
20. Assertion: Biodegradable substances result in the formation of compost and natural replenishment. Reason: It is due to breakdown of complex inorganic substances into simple organic substances.
The correct option is A is true but R is false. Biodegradable substances are complex organic substances that are broken down into simple inorganic substances. The assertion is correct, but the reason is incorrect.
21. Dil. HCl is added to Zn granules. How will you prove that a chemical change has taken place here? Support your response with two arguments.
You can prove a chemical change has taken place by observing two things. First, the evolution of a gas (hydrogen), which can be confirmed by a “pop” sound when a flame is brought near the test tube. Second, an increase in temperature, as this is an exothermic reaction that releases heat.
22. State the post-fertilization changes that lead to fruit formation in plants.
After fertilization, the following changes occur to form a fruit. The ovules inside the ovary develop into seeds, and the ovary itself matures and swells to form the fruit. The other floral parts generally wither and fall off.
23. What is the purpose of making urine in the human body? Name the organs that store and release the urine.
The main purpose of making urine is to filter waste products from the blood, such as urea, and remove them from the body. Urine is stored in the urinary bladder and released through the urethra.
OR
Why do arteries have thick and elastic walls whereas veins have valves?
Arteries have thick and elastic walls to withstand the high pressure of blood being pumped from the heart. Veins, on the other hand, carry blood under low pressure and have valves to prevent the backflow of blood, ensuring it flows towards the heart.
24. The refractive indices of three media are given below: Medium A: 1.6, B: 1.8, C: 1.5. A ray of light is travelling from A to B and another ray is travelling from B to C. (a) In which of the two cases the refracted ray bends towards the normal? (b) In which case does the speed of light increase in the second medium? Give reasons for your answer.
a) The refracted ray bends towards the normal when light travels from a rarer to a denser medium. This occurs when it travels from Medium A to Medium B because the refractive index increases from 1.6 to 1.8.
b) The speed of light increases when it travels from a denser to a rarer medium. This happens when it travels from Medium B to Medium C because the refractive index decreases from 1.8 to 1.5.
25. A piece of wire of resistance R is cut into three equal parts. These parts are then connected in parallel. If the equivalent resistance of this parallel combination is R1, what is the value of the ratio R1:R?
The resistance of each of the three equal parts is R/3. When connected in parallel, the equivalent resistance R1 is calculated as 1/R1=1/(R/3)+1/(R/3)+1/(R/3), which simplifies to 1/R1=9/R. Therefore, R1=R/9, and the ratio R1:R is 1:9.
OR
Refer to the image below and state how the magnetic field pattern indicates regions where the magnetic field is stronger outside the magnet? What happens to the magnetic field when the current in the circuit is reversed?
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The magnetic field is stronger where the magnetic field lines are more crowded or dense. In the case of a solenoid, this is at the poles. When the current is reversed, the direction of the magnetic field also reverses, causing the North and South poles to switch.
26. Study the food chain given below and answer the questions that follow: Leaf -> Caterpillar -> Chameleon -> Snake -> Mongoose
a) If the amount of energy available at the third trophic level is 100 joules, then how much energy will be available at the producer level? Justify your answer.
The amount of energy at the producer level (Leaf) would be 10,000 joules. This is based on the 10% law of energy transfer, which states that only about 10% of the energy is transferred from one trophic level to the next.
b) Is it possible to have 2 more trophic levels in this food chain just before the fourth trophic level? Justify your answer.
It is not possible. A food chain rarely has more than 4-5 trophic levels. This is because at each level, a large amount of energy is lost. By the time energy reaches higher trophic levels, it is insufficient to support another level of organisms.
27. The given reaction shows one of the processes to extract the metals like Iron and Manganese. MnO2(s)+Al(s)→Mn(l)+Al2O3(s)+Heat. a) Give a reason why the above reaction is known as a thermite reaction. b) Identify the substance oxidized and reduced in the above reaction. c) Give a reason why Aluminium is preferably used in thermite reactions.
a) This reaction is called a thermite reaction because it is a highly exothermic redox reaction that produces a huge amount of heat, enough to melt the metal produced.
b) Aluminum (Al) is oxidized as it gains oxygen. Manganese dioxide (MnO2) is reduced as it loses oxygen.
c) Aluminum is preferred because it is a highly reactive metal. Its high reactivity allows it to displace less reactive metals from their oxides, releasing a large amount of energy in the process.
28. An element ‘X’ is a pale yellow crystalline solid and has an octatomic molecule, X8. It burns in air to form a pungent smell gas ‘Y’, which is also formed when copper is heated with conc. H2SO4. (a) Identify the elements X and the gas Y. (b) Write the chemical reaction of X with oxygen. (c) Write the chemical reaction of Y with water.
a) The element ‘X’ is Sulphur (S). The gas ‘Y’ is Sulphur dioxide (SO2).
b) The chemical reaction is: S8(s)+8O2(g)→8SO2(g).
c) The chemical reaction is: SO2(g)+H2O(l)→H2SO3(aq) (Sulphurous acid).
OR
A student mixes a solution of lead(II) nitrate and potassium iodide. a) What type of reaction is this? b) What is the colour of the precipitate formed? Name the compound. c) What will happen if excess zinc is added to the above reaction mixture?
a) This is a double displacement reaction, where the ions of the two reactants exchange to form new products.
b) A bright yellow precipitate is formed. The compound is lead(II) iodide (PbI2).
c) If excess zinc is added, nothing will happen. This is because zinc is more reactive than lead, but it cannot displace lead from the insoluble solid precipitate of lead(II) iodide.
29. The diagram below shows a part of the human excretory system. (a) Name the parts labelled A and B. (b) What is the main function of the part labelled A? (c) How is the process of urination regulated?
a) A is the kidney and B is the ureter.
b) The main function of the kidney (A) is to filter the blood to remove waste products and produce urine.
c) The process of urination is regulated by nerve signals from the bladder to the brain and the muscular sphincters that control the release of urine.
OR
(a) State the role of the pancreas in the digestion of food. (b) Name the two components of the pancreatic juice. (c) State the function of each component.
a) The pancreas plays a crucial role in digestion by producing pancreatic juice, which contains a variety of digestive enzymes.
b) Two main components of the pancreatic juice are trypsin and lipase.
c) Trypsin helps to digest proteins, while lipase helps to digest fats.
30. Name the device used to produce electric current. With the help of a labeled diagram, explain the working of this device. Mention the principle on which it works.
The device used is an electric generator.
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It works on the principle of electromagnetic induction, where an electric current is induced in a coil when it is rotated in a magnetic field. The rotation causes the magnetic flux through the coil to change, which produces a current.
OR
What is the function of a fuse in a circuit? Explain the heating effect of electric current. How does it help in the working of a fuse?
The function of a fuse is to protect an electrical circuit and its appliances from excessive current. It acts as a safety device. The heating effect of electric current is the production of heat as current flows through a resistor. A fuse uses a wire with a low melting point. When a dangerously high current flows, the wire heats up and melts, breaking the circuit and stopping the current.
31. (a) Explain the formation of the following compounds with the electron dot structure. (i) Sodium Chloride (ii) Magnesium Chloride (b) Why do ionic compounds have high melting points?
a) Sodium Chloride (NaCl): A sodium atom donates its single valence electron to a chlorine atom. This forms a positively charged sodium ion (Na+) and a negatively charged chloride ion (Cl−) which are held together by a strong electrostatic force.
Magnesium Chloride (MgCl2): A magnesium atom donates its two valence electrons, one to each of two chlorine atoms. This forms a positively charged magnesium ion (Mg2+) and two negatively charged chloride ions (Cl−) which are held together by strong electrostatic forces.
b) Ionic compounds have high melting points because of the very strong electrostatic forces of attraction between the oppositely charged ions. A large amount of energy is needed to overcome these forces and melt the compound.
32. (a) What is the relationship between the angle of incidence and the angle of reflection? (b) Draw a ray diagram to show the formation of the image of a concave lens. State the characteristics of the image formed. (c) A convex lens of focal length 20 cm is placed in contact with a concave lens of focal length 10 cm. Calculate the power of the combination.
a) The relationship is that the angle of incidence is always equal to the angle of reflection.
b) The image formed by a concave lens is always virtual, erect, and diminished.
c) The power of the convex lens is 1/0.2m=+5D. The power of the concave lens is 1/(−0.1m)=−10D. The power of the combination is the sum of the powers, which is +5D+(−10D)=−5D.
33. (a) Why is it not possible to construct an ecosystem in an aquarium by placing a few fishes, some plants, water, and some sand? (b) Suggest four ways that you can adopt to reduce the consumption of electricity in your household. (c) Why is damage to the ozone layer a cause of concern? What are the causes of this damage?
a) It is not possible to create a sustainable ecosystem with only these components because a vital part, decomposers, is missing. Decomposers are needed to break down waste and recycle nutrients for the plants.
b) Four ways to reduce electricity consumption are: using energy-efficient appliances, unplugging electronics when not in use, maximizing the use of natural light, and using insulation to regulate indoor temperatures.
c) Damage to the ozone layer is a concern because it allows harmful ultraviolet (UV) radiation from the sun to reach the Earth, which can cause skin cancer and other health issues. This damage is primarily caused by chlorofluorocarbons (CFCs), which were used in refrigerants and aerosols.orocarbons (CFCs).olution is basic (higher pH).
For the official Class 10 Mathematics Solutions, you can visit:
- NCERT Textbooks (for Class 10):
Class-wise Solutions
Class 12:
Class 12 Physics – NCERT Solutions
Class 12 Chemistry – NCERT Solutions
Class 11:
- Class 11 Physics – NCERT Solutions
- Class 11 Chemistry – NCERT Solutions
- Class 11 Biology – NCERT Solutions
- Class 11 Math – NCERT Solutions
Class 10:
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Class 8:
Class 7:
Class 6:
The CBSE Class 10 Science Sample Paper 2023-24 is a valuable tool for students preparing for their board exams. It not only familiarizes students with the new question pattern but also sharpens their problem-solving and analytical thinking skills. By solving all sections — including objective, case-based, and competency-based questions — students can strengthen their grasp on Physics, Chemistry, and Biology topics in a structured manner.
Moreover, the solutions provided for the CBSE Class 10 Science Sample Paper 2023-24 are explained in simple language, following the NCERT-based approach, which ensures clarity and accuracy. It is highly recommended that students review the marking scheme and answer structure through these solved examples to maximize their performance in the actual exam.
In conclusion, the CBSE Class 10 Science Sample Paper 2023-24 is more than just a practice resource—it is a complete guide for effective revision and exam strategy. Students who solve it thoroughly and learn from the solutions are more likely to perform well and score higher in their final board examination.