CBSE Class 10 Science Pre-Board Sample Paper 2026-27 with Solutions

The CBSE Class 10 Science Pre-Board Sample Paper 2026-27 is designed to help students prepare for the upcoming CBSE Board Exams 2027 by giving them an opportunity to practise questions based on the latest examination pattern. The practice paper covers all three major sections: Biology, Chemistry and Physics with a balanced mix of multiple-choice questions, assertion-reason questions, short-answer questions, long-answer questions and competency-based questions.

With the board examination approaching, solving a full-length pre-board sample paper can help students understand the question paper structure, assess their subject knowledge and improve time management. Students can practise the questions given below, check the section-wise marks distribution and refer to the detailed answer key and marking scheme to evaluate their performance.

Also Read l CBSE Class 10 Science Syllabus 2026-27

CBSE 10th Science 2027: Section-Wise Question Distribution and Marks

CBSE Class 10 Science Pre-Board Sample Paper 2026-27

General Instructions

1. The question paper contains 39 questions divided into three sections: A (Biology), B (Chemistry) and C (Physics).

All questions are compulsory. Internal choices are provided in selected questions.

Draw neat, labelled diagrams wherever required.

Use appropriate units in numerical answers.

Attempt only one alternative wherever an internal choice is given.

Section A: Biology (30 Marks)

Questions 1-9 carry 1 mark each.

Q1. Which of the following events takes place during photosynthesis?

A. Oxygen is used to break down glucose.
B. Carbon dioxide is converted into carbohydrates.
C. Nitrogen is converted into proteins directly.
D. Water is produced by the breakdown of glucose.

Q2. Which part of the nephron is primarily responsible for filtration of blood?

A. Collecting duct
B. Glomerulus
C. Loop of Henle
D. Ureter

Q3. A plant shoot bends towards sunlight. This movement is an example of:

A. Geotropism
B. Hydrotropism
C. Phototropism
D. Chemotropism

Q4. Which of the following is the correct function of the placenta?

A. It produces sperms.
B. It transfers nutrients and oxygen from mother to embryo.
C. It prevents the formation of the embryo.
D. It stores urine during pregnancy.

Q5. In a human female, fertilisation normally takes place in the:

A. Uterus
B. Ovary
C. Oviduct
D. Vagina

Q6. If a tall pea plant (Tt) is crossed with a dwarf pea plant (tt), what percentage of the offspring will be dwarf?

A. 0%
B. 25%
C. 50%
D. 100%

Q7. In a food chain, green plants occupy which trophic level?

A. First
B. Second
C. Third
D. Fourth

Q8. Assertion (A): The human heart has four chambers.

Reason (R): Separation of oxygenated and deoxygenated blood helps ensure an efficient oxygen supply to the body.

Choose the correct option:

A. Both A and R are true, and R correctly explains A.
B. Both A and R are true, but R does not explain A.
C. A is true, but R is false.
D. A is false, but R is true.

Q9. Assertion (A): Energy available at each successive trophic level decreases.

Reason (R): Only about 10% of the energy is transferred from one trophic level to the next.

Choose the correct option:

A. Both A and R are true, and R correctly explains A.
B. Both A and R are true, but R does not explain A.
C. A is true, but R is false.
D. A is false, but R is true.

Questions 10-12 carry 2 marks each.

Q10. Why is the small intestine longer in herbivores than in carnivores? Explain with reference to the digestion of food.

Q11. What is a reflex action? Explain the role of the spinal cord in controlling reflex actions with one suitable example.

OR

How do plant hormones help in the growth and movement of plants? Explain the role of auxin in the bending of a shoot towards light.

Q12. State two changes that take place in the uterus after the implantation of an embryo.

Questions 13-14 carry 3 marks each.

Q13. Explain how oxygen and carbon dioxide are transported in the human body. Mention the role of haemoglobin.

Q14. Consider the food chain:

Grass → Grasshopper → Frog → Snake

Answer the following:

(a) Identify the producer and the secondary consumer. (1)
(b) If the grass contains 10,000 J of energy, calculate the energy available to the frog using the 10% law. (1)
(c) Why do harmful chemicals become more concentrated at higher trophic levels? (1)

Q15. carries 4 marks.

Q15. A student crosses a pure-breeding tall pea plant with a pure-breeding dwarf pea plant.

(a) Write the genotypes of the two parent plants. (1)
(b) State the genotype and phenotype of the F1 generation. (1)
(c) Show the cross between two F1 plants and calculate the phenotypic ratio in the F2 generation. (2)

Q16. carries 5 marks.

Q16. Explain the process of nutrition in human beings by answering the following:

(a) Where does digestion of starch begin? Name the enzyme involved. (1)
(b) What is the role of hydrochloric acid in the stomach? (1)
(c) Explain the role of bile juice in digestion. (1)
(d) How are digested food materials absorbed in the small intestine? (1)
(e) What is the function of the large intestine? (1)

OR

Explain the process of double circulation in human beings. Why is it necessary to keep oxygenated and deoxygenated blood separate?

Also Read l CBSE Class 10 Sample Paper: Science

Section B: Chemistry (25 Marks)

Questions 17-24 carry 1 mark each.

Q17. Which of the following is a combination reaction?

A. CaO + H₂O → Ca(OH)₂
B. 2AgCl → 2Ag + Cl₂
C. Zn + CuSO₄ → ZnSO₄ + Cu
D. Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl

Q18. A solution has a pH of 2. It is most likely to be:

A. Strongly acidic
B. Weakly basic
C. Neutral
D. Strongly basic

Q19. Which gas is released when an active metal reacts with dilute hydrochloric acid?

A. Oxygen
B. Hydrogen
C. Nitrogen
D. Carbon dioxide

Q20. Assertion (A): Ionic compounds generally have high melting points.

Reason (R): Strong electrostatic forces of attraction exist between oppositely charged ions.

Choose the correct option:

A. Both A and R are true, and R correctly explains A.
B. Both A and R are true, but R does not explain A.
C. A is true, but R is false.
D. A is false, but R is true.

Q21. Which of the following is a saturated hydrocarbon?

A. Ethene
B. Ethyne
C. Ethane
D. Benzene

Q22. Which metal is stored in kerosene to prevent its reaction with air and moisture?

A. Copper
B. Sodium
C. Iron
D. Silver

Q23. Which of the following salts is used in the preparation of washing soda?

A. Sodium chloride
B. Sodium carbonate
C. Calcium carbonate
D. Sodium hydrogen carbonate

Q24. Which functional group is present in ethanoic acid?

A. Alcohol
B. Aldehyde
C. Carboxylic acid
D. Ketone

Q25 carries 2 marks.

Q25. Balance the following chemical equation and identify the type of reaction:

Fe + H₂O → Fe₃O₄ + H₂

Q26 carries 3 marks.

Q26. A metal X reacts with oxygen to form an oxide Y. The oxide reacts with both acids and bases.

(a) What is the nature of oxide Y? (1)
(b) Give one example of such an oxide. (1)
(c) Write one balanced chemical equation to show its reaction with an acid or a base. (1)

OR

Explain why metals such as gold and platinum are often found in their free state in nature. Name one process used for refining copper.

Q27 carries 3 marks.

Q27. Answer the following questions about carbon compounds:

(a) What is catenation? (1)
(b) Why does carbon form a large number of compounds? State two reasons. (1)
(c) Write the structural formula of ethanol. (1)

Q28 carries 4 marks.

Q28. A student performs an experiment by adding dilute hydrochloric acid to sodium carbonate.

(a) Name the gas evolved. (1)
(b) How can the gas be tested in the laboratory? (1)
(c) Write the balanced chemical equation for the reaction. (1)
(d) What happens when the gas is passed through lime water in excess? (1)

Q29 carries 5 marks.

Q29. Answer the following questions:

(a) What is a homologous series? (1)
(b) Write the molecular formula of the first two members of the alkane series. (1)
(c) What is the difference between addition and substitution reactions? (1)
(d) Write the chemical equation for the reaction of ethanol with ethanoic acid in the presence of concentrated sulphuric acid. Name the product formed. (2)

OR

(a) Define oxidation and reduction in terms of oxygen and hydrogen. (2)
(b) What happens when copper powder is heated in air? Write the balanced equation. (1)
(c) How can the original copper be obtained from the black product? Write the chemical equation. (2)

Also Check: CBSE Class 10 Science Marks Distribution 2026-27: Unit-Wise Weightage, Theory and Internal Assessment

Section C: Physics (25 Marks)

Questions 30-32 carry 1 mark each.

Q30. The image formed by a concave mirror when an object is placed beyond the centre of curvature is:

A. Virtual, erect and enlarged
B. Real, inverted and diminished
C. Real, erect and diminished
D. Virtual, inverted and enlarged

Q31. The SI unit of electric resistance is:

A. Volt
B. Ampere
C. Ohm
D. Watt

Q32. Assertion (A): A convex lens can form both real and virtual images.

Reason (R): The nature of the image formed by a convex lens depends on the position of the object relative to the lens.

Choose the correct option:

A. Both A and R are true, and R correctly explains A.
B. Both A and R are true, but R does not explain A.
C. A is true, but R is false.
D. A is false, but R is true.

Questions 33-34 carry 2 marks each.

Q33. State Ohm’s law. Write its mathematical expression and explain the meaning of the symbols used.

Q34. Two resistors of 4 Ω and 6 Ω are connected in series. Calculate their equivalent resistance. What will be the current flowing through the circuit if a 10 V battery is connected across them?

Questions 35-37 carry 3 marks each.

Q35. An object is placed 30 cm in front of a concave mirror of focal length 15 cm.

(a) Write the mirror formula. (1)
(b) Calculate the image distance. (1)
(c) State the nature of the image formed. (1)

Q36. Explain the magnetic field produced by a current-carrying straight conductor.

(a) What is the shape of the magnetic field lines? (1)
(b) State the right-hand thumb rule. (1)
(c) What happens to the strength of the magnetic field when the current is increased? (1)

Q37. An electric bulb is rated 100 W, 220 V.

(a) Calculate the current drawn by the bulb. (1)
(b) Calculate its resistance. (1)
(c) Calculate the electrical energy consumed in 5 hours in kWh. (1)

Q38 carries 4 marks.

Q38. A student uses a convex lens to form an image of an object placed 30 cm from the lens. The focal length of the lens is 20 cm.

(a) Write the lens formula. (1)
(b) Calculate the image distance. (2)
(c) State whether the image is real or virtual. (1)

Q39 carries 5 marks.

Q39. Answer the following questions related to electricity:

(a) Define electric power and write its SI unit. (1)
(b) State two factors on which the resistance of a conductor depends. (1)
(c) Two resistors of 3 Ω and 6 Ω are connected in parallel. Calculate their equivalent resistance. (2)
(d) Why are household electrical appliances connected in parallel? (1)

OR

(a) State Joule’s law of heating. (1)
(b) Write the mathematical expression for heat produced in a resistor. (1)
(c) An electric heater of resistance 44 Ω is connected to a 220 V supply. Calculate the current flowing through it and the power consumed. (2)
(d) Why is a fuse wire connected in series with an electrical appliance? (1)

Also Read l CBSE Class 10 Exam Pattern 2027

CBSE Class 10 Section A: Biology Solutions

Q. No.Correct answer / key points

1. B- Carbon dioxide is converted into carbohydrates.

2. B- Glomerulus

3. C- Phototropism

4. B- Transfers nutrients and oxygen from mother to embryo.

5. C- Oviduct

6. C- 50%

7. A- First trophic level

8. A- Both statements are true and R explains A.

9. A- Both statements are true and R explains A.

CBSE Class 10 Science Internal Assessment 2026-27

The internal assessment will continue as before, carrying 20 marks based on the following components: