Sample Question Paper
Class: X Session: 2025-26 Subject: Science (Subject Code: 086)
Maximum Marks: 80 Time Allowed: 3 hours
General Instructions:
This question paper consists of 39 questions in 5 sections.
All questions are compulsory. However, an internal choice is provided in some questions. A student is expected to attempt only one of these questions.
Section A consists of 20 objective-type questions carrying 1 mark each.
Section B consists of 6 Very Short Answer questions carrying 2 marks each. Answers to these questions should be in the range of 30 to 50 words.
Section C consists of 7 Short Answer questions carrying 3 marks each. Answers to these questions should be in the range of 50 to 80 words.
Section D consists of 3 Long Answer questions carrying 5 marks each. Answers to these questions should be in the range of 80 to 120 words.
Section E consists of 3 source-based/case-based units of assessment of 4 marks each with sub-parts.
SECTION - A
(Select and write one most appropriate option out of the four options given for each of the questions 1 – 20. There is no negative marking for incorrect response.)
1. A student adds a few drops of universal indicator to a dilute solution of sodium bicarbonate. The colour of the solution will turn to: (a) Orange (b) Bluish-green (c) Red (d) Lemon yellow
2. Which of the following represents the correct order of reactivity of the given metals? (a) Na > Mg > Al > Cu (b) Mg > Na > Al > Cu (c) Na > Mg > Cu > Al (d) Al > Na > Mg > Cu
3. The structural formula of an ester is H-COO-CH₂-CH₃. The IUPAC name of the alcohol and the carboxylic acid from which it is formed are: (a) Methanol and Propanoic acid (b) Ethanol and Methanoic acid (c) Methanol and Ethanoic acid (d) Propanol and Methanoic acid
4. A white salt on heating decomposes to give brown fumes and a yellow residue is left behind. The salt is: (a) Lead carbonate (b) Lead nitrate (c) Zinc carbonate (d) Silver chloride
5. In the electrolytic refining of copper, the electrolyte solution is: (a) Aqueous solution of Copper sulphate (b) Aqueous solution of Copper chloride (c) Molten Copper chloride (d) Aqueous solution of Sodium chloride
6. The process of respiration is: (a) An endothermic process (b) An exothermic process (c) A reduction process (d) A physical process
7. In human males, the testes are located in the scrotum outside the abdominal cavity because: (a) It helps in the secretion of male hormones. (b) It provides more space for the formation of sperms. (c) It helps in maintaining a lower temperature required for sperm formation. (d) It protects the testes from physical shocks.
8. In a pea plant, a pure tall plant (TT) is crossed with a pure short plant (tt). The ratio of pure tall plants to pure short plants in the F2 generation will be: (a) 1:3 (b) 3:1 (c) 1:1 (d) 2:1
9. The functional unit of a kidney is: (a) Neuron (b) Nephron (c) Glomerulus (d) Ureter
10. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. The position of the image is: (a) 6 cm behind the mirror (b) 6 cm in front of the mirror (c) 30 cm behind the mirror (d) 30 cm in front of the mirror
11. The splitting of white light into its component colours is called: (a) Reflection (b) Refraction (c) Dispersion (d) Scattering
12. A cylindrical conductor of length 'l' and uniform area of cross-section 'A' has resistance 'R'. Another conductor of length 2.5l and resistance 0.5R of the same material has an area of cross-section: (a) 5A (b) 2.5A (c) 0.5A (d) 1/5 A
13. The magnetic field inside a long straight solenoid carrying current: (a) is zero. (b) decreases as we move towards its end. (c) increases as we move towards its end. (d) is the same at all points.
14. Which of the following constitutes a food chain? (a) Grass, wheat and mango (b) Grass, goat and human (c) Goat, cow and elephant (d) Grass, fish and goat
15. Which of the following is not a part of the female reproductive system in human beings? (a) Ovary (b) Uterus (c) Vas deferens (d) Fallopian tube
16. The device used for producing electric current is called a: (a) Galvanometer (b) Ammeter (c) Generator (d) Motor
For Questions 17 to 20, two statements are given – one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below: (a) Both (A) and (R) are true and (R) is the correct explanation of (A). (b) Both (A) and (R) are true, but (R) is not the correct explanation of (A). (c) (A) is true, but (R) is false. (d) (A) is false, but (R) is true.
17. Assertion (A): A geneticist crossed a pea plant having violet flowers with a pea plant with white flowers, he got all violet flowers in F1 generation. Reason (R): White colour gene is not passed on to the next generation.
18. Assertion (A): The sky appears blue in the daytime. Reason (R): White light is composed of seven colours. The blue light is scattered more than other colours by the atmospheric particles.
19. Assertion (A): The burning of natural gas is an endothermic process. Reason (R): Methane gas combines with oxygen to produce carbon dioxide and water.
20. Assertion (A): A compass needle shows deflection when placed near a current-carrying wire. Reason (R): A current-carrying conductor produces a magnetic field around it.
SECTION - B
21. Identify the type of chemical reaction in the following statements and write the balanced chemical equation for each: (i) A solution of potassium chloride when mixed with silver nitrate solution, an insoluble white substance is formed. (ii) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form a solid magnesium nitride.
22. How is ozone formed in the upper atmosphere? Why is its depletion a cause for concern?
OR
What is biomagnification? Explain with the help of an example.
23. Name two hormones secreted by the pancreas. Write one function of each.
24. An object of height 4 cm is placed at a distance of 20 cm in front of a concave lens of focal length 10 cm. Find the position, nature, and size of the image formed.
25. What is meant by the resistance of a conductor? Name and define its SI unit. On what factors does the resistance of a conductor depend?
26. Why do Mendel's experiments with pea plants have a greater significance than those of his predecessors? Give two reasons.
SECTION - C
27. A metal 'X' is found in nature as its sulphide XS. It is used in galvanization. The sulphide ore is roasted to form its oxide which is then reduced to get the metal 'X'. (i) Identify the metal 'X'. (ii) Write the chemical equation for the roasting of its sulphide ore. (iii) Write the chemical equation for the reduction of its metal oxide.
28. What are homologous series of carbon compounds? List any two characteristics of a homologous series.
29. (a) Draw a neat diagram of the human excretory system and label the following parts: (i) Kidney (ii) Ureter (iii) Urinary bladder (iv) Urethra (b) How is urine produced and eliminated?
30. What is a reflex arc? Draw a schematic diagram to show a reflex arc. Label the sensory neuron and motor neuron.
31. (a) What is presbyopia? (b) What are its causes? (c) How is it corrected?
OR
A person needs a lens of power -2.5 D for correcting his distant vision and a lens of power +1.5 D for correcting his near vision. (i) What kind of defect of vision does he have? (ii) Find the focal length of the lens required for correcting his distant vision and near vision.
32. What is an electromagnet? How is it different from a permanent magnet? Give two uses of an electromagnet.
33. What are trophic levels? Why do we have a limited number of trophic levels in a food chain?
SECTION - D
34. (a) An organic compound 'A' with molecular formula C₂H₆O is an active ingredient of all alcoholic drinks. Identify 'A'. (b) How is 'A' converted to ethanoic acid? Write the chemical equation. (c) What happens when 'A' reacts with sodium metal? Write the chemical equation for the reaction. (d) Differentiate between saturated and unsaturated hydrocarbons with one example of each.
OR
(a) Explain the cleansing action of soap. (b) What is hydrogenation? What is its industrial application? (c) Why are carbon and its compounds used as fuels for most applications?
35. (a) Describe the process of double circulation in human beings with the help of a diagram. (b) Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
OR
(a) Draw a diagram of the longitudinal section of a flower and label the following parts: (i) Stigma (ii) Anther (iii) Ovary (iv) Sepal (b) What is pollination? Differentiate between self-pollination and cross-pollination. (c) Mention the post-fertilization changes that occur in a flower.
36. (a) State Ohm's law. Draw a V-I graph for an ohmic conductor. (b) Three resistors of resistances R₁, R₂, and R₃ are connected (i) in series and (ii) in parallel. Derive an expression for the equivalent resistance in each case. (c) In the circuit diagram given below, find the total resistance of the circuit and the total current flowing in the circuit.
SECTION - E
(Question numbers 37-39 are case-based/data-based questions with 2 to 3 short sub-parts. In these questions, attempt all the parts.)
37. Read the following and answer the questions.
The pH scale is used to measure the acidity or alkalinity of a solution. The scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is alkaline. The table below shows the pH values of four solutions.
Solution | pH value |
|---|---|
A | 4 |
B | 9 |
C | 7 |
D | 1 |
(i) Which solution is the most acidic? (1) (ii) Arrange the solutions in increasing order of their hydrogen ion concentration. (1) (iii) What would be the effect of solution B on blue litmus paper and red litmus paper? (2)
OR
(iii) If a strong acid is added to solution B, what will happen to its pH? Give a reason. (2)
38. Read the following and answer the questions.
A couple has four children, two sons and two daughters. The mother is colour-blind, while the father has normal vision. Colour blindness is an X-linked recessive trait. Let 'Xc' represent the allele for colour blindness and 'X' represent the allele for normal vision.
(i) What will be the genotype of the mother and the father? (1) (ii) What is the probability that a son will be colour-blind? Show with a cross. (2) (iii) What is the probability of a daughter being a carrier of the colour-blindness gene? (1)
39. Read the following and answer the questions.
When a beam of light enters a prism, it gets refracted and splits into its seven constituent colours. This phenomenon is known as dispersion. The band of seven colours obtained is called a spectrum. Red light bends the least, while violet light bends the most. This is because different colours of light travel at different speeds in a medium other than a vacuum.
(i) Why does a prism split white light into different colours? (1) (ii) Which colour of the spectrum has the longest wavelength? (1) (iii) Explain the recombination of the spectrum of white light using two identical prisms. Draw a labelled diagram for it. (2)
