Last-Minute Revision for CBSE Class 10 Science Compartment Exam 2025: 50 Crucial MCQs with Responses (July 17)
**Top 50 MCQs with Answers for CBSE Class 10 Science Exam 2025**
Prepare for the CBSE Class 10 Science (2025) exam with these high-value, widely repeated, and conceptual MCQs. These questions cover all major units and are designed to help students prepare effectively.
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### Chemical Reactions and Equations
1. **Which of the following is a physical change?** (a) Burning of paper (b) Digestion of food (c) Melting of ice (d) Rusting of iron **Answer:** (c) Melting of ice
2. **Which of the following is a decomposition reaction?** (a) CaO + H₂O → Ca(OH)₂ (b) Fe + CuSO₄ → FeSO₄ + Cu (c) 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂ (d) CH₄ + O₂ → CO₂ + H₂O **Answer:** (c) 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
3. **The chemical formula of rust is:** (a) Fe₂O₃·xH₂O (b) FeO (c) Fe₃O₄ (d) Fe₂O₃ **Answer:** (a) Fe₂O₃·xH₂O
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### Acids, Bases, and Salts
4. **An indicator turns red in acidic solution and yellow in basic solution. It is:** (a) Phenolphthalein (b) Methyl orange (c) Litmus (d) Bromothymol blue **Answer:** (b) Methyl orange
5. **The pH of gastric juice is about:** (a) 1.5 (b) 7.0 (c) 8.5 (d) 13.0 **Answer:** (a) 1.5
6. **Milk of magnesia is:** (a) Mg(OH)₂ (b) MgCl₂ (c) MgSO₄ (d) Mg(NO₃)₂ **Answer:** (a) Mg(OH)₂
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### Metals and Non-metals
7. **Which of the following will displace zinc from its salt solution?** (a) Silver (b) Copper (c) Lead (d) Magnesium **Answer:** (d) Magnesium (A metal above zinc in the reactivity series can displace it.)
8. **Which of the following is not a metal?** (a) Sodium (b) Bromine (c) Iron (d) Aluminium **Answer:** (b) Bromine
9. **The most abundant metal in the Earth’s crust is:** (a) Iron (b) Aluminium (c) Sodium (d) Calcium **Answer:** (b) Aluminium
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### Carbon and its Compounds
10. **The functional group in an alcohol is:** (a) –CHO (b) –COOH (c) –CO (d) –OH **Answer:** (d) –OH
11. **Which hydrocarbon has a double bond?** (a) Methane (b) Ethene (c) Ethane (d) Ethyne **Answer:** (b) Ethene
12. **Soaps are sodium/potassium salts of:** (a) Boric acid (b) Hydrochloric acid (c) Fatty acids (d) Citric acid **Answer:** (c) Fatty acids
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### Life Processes
13. **The site of photosynthesis in green plants is:** (a) Mitochondria (b) Chloroplast (c) Ribosome (d) Leucoplast **Answer:** (b) Chloroplast
14. **The breakdown of glucose in the presence of oxygen is called:** (a) Anaerobic respiration (b) Photosynthesis (c) Aerobic respiration (d) Transpiration **Answer:** (c) Aerobic respiration
15. **Where does digestion of food begin in the human body?** (a) Stomach (b) Mouth (c) Small intestine (d) Large intestine **Answer:** (b) Mouth
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### Control and Coordination
16. **Which part of the brain controls body temperature, hunger, and thirst?** (a) Cerebrum (b) Cerebellum (c) Medulla (d) Hypothalamus **Answer:** (d) Hypothalamus
17. **Which hormone is responsible for regulating blood sugar?** (a) Insulin (b) Adrenaline (c) Thyroxine (d) Growth hormone **Answer:** (a) Insulin
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### Electricity
18. **The SI unit of electric current is:** (a) Volt (b) Ampere (c) Ohm (d) Watt **Answer:** (b) Ampere
19. **If two bulbs of 100 W and 40 W are connected in series and the current through the 100 W bulb is 1 A, the current through the 40 W bulb will be:** (a) 0.4 A (b) 0.6 A (c) 0.8 A (d) 1 A **Answer:** (d) 1 A (In series, current remains same through all components)
20. **The maximum resistance which can be made using four resistors each of 2 Ω is:** (a) 2 Ω (b) 4 Ω (c) 8 Ω (d) 16 Ω **Answer:** (c) 8 Ω (Resistors in series)
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### Magnetic Effects of Electric Current
21. **The direction of magnetic field lines inside a bar magnet is from:** (a) North to South pole (b) South to North pole (c) Neither (d) Both **Answer:** (b) South to North pole
22. **Which device converts electrical energy into mechanical energy?** (a) Generator (b) Motor (c) Transformer (d) Galvanometer **Answer:** (b) Motor
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### Heredity and Evolution
23. **Which scientist gave the laws of inheritance?** (a) Charles Darwin (b) Gregor Mendel (c) Robert Hooke (d) Albert Einstein **Answer:** (b) Gregor Mendel
24. **Which of the following is not a sex trait?** (a) Colour blindness (b) Height (c) Haemophilia (d) Skin colour **Answer:** (d) Skin colour
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### Periodic Classification of Elements
25. **Elements with similar properties are placed in the same:** (a) Period (b) Group (c) Orbit (d) Atom **Answer:** (b) Group
26. **Which of the following is a noble gas?** (a) Neon (b) Sodium (c) Oxygen (d) Aluminium **Answer:** (a) Neon
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### Miscellaneous & Conceptual Questions
27. **In electrolysis of water, why is the volume of gas collected over one electrode double that collected over the other electrode?** **Answer:** Because water (\(H_2O\)) splits into hydrogen and oxygen in a 2:1 ratio by volume (\(2H_2O \rightarrow 2H_2 + O_2\))
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## How to Access Full Question Sets
- **Download 2025 Question Papers and Solutions:** For the latest set-wise MCQs and answers, check the CBSE 10th 2025 Science question paper PDFs and solutions provided by educational portals and official sources. - **NCERT Exemplars:** Download chapter-wise exemplar questions for more practice. - **Official Answer Key:** Unofficial answer keys with detailed explanations are often released online after the exam.
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## Conclusion
This selection covers high-yield MCQs likely to appear in the CBSE Class 10 Science 2025 exam. For a comprehensive set of 50 questions (and beyond), always refer to official sample papers, previous years’ question papers, and NCERT exemplar problems for thorough preparation. Remember, practicing with answer keys and solutions is essential for identifying common patterns and understanding the reasoning behind each answer.
[1] [CBSE Class 10 Science MCQs with Solutions](https://www.edurev.in/questions/cbse-class-10-science-mcqs-with-solutions) [2] [NCERT Exemplar Problems for Class 10 Science](https://www.ncert.nic.in/textbook/10th/science/exemplarsolutions/10_1.pdf) [3] [CBSE Sample Papers for Class 10 Science](https://www.cbseacademic.nic.in/web_material/samplepapers/Science/Class10/2018-19/Science_10_2018-19.pdf) [4] [CBSE 10th Science MCQs with Answers](https://www.studytonight.com/class-10-science/mcqs-class-10-science) [5] [CBSE Class 10 Science Question Paper 2025 PDF](https://www.cbseacademic.nic.in/web_material/question_papers/Class_10/Science/2025-2026/Science_2025-26.pdf)
- The process of learning new concepts in science is essential for success in the CBSE Class 10 Science 2025 exam.
- A well-rounded education-and-self-development regime should also include learning about chemical reactions, such as the decomposition reaction represented by the chemical equation 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂.
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