What makes a question "CBSE-style"

CBSE papers since 2023 lean heavily on competency-based questions — source-based or case-study items where students apply a concept to an unfamiliar situation rather than recall a definition. Board papers also carry internal choice in the higher mark-value questions and expect NCERT-exact terminology in Science and Social Science answers, since evaluators map answers to the official marking scheme point by point.

When you paste NCERT exercise or previous-year questions as your source, the generator mirrors that structure — case-based stems, stepwise numericals, and value-based Social Science questions — instead of generic trivia.

Curated CBSE Class 10 Science Question Pool

Click the action button below to start solving a CBSE-style test derived directly from this textbook sample.

1. Define the term 'refraction of light' and state Snell's law.
2. A resistor of 10Ω is connected to a 5V battery. Find the current flowing through the circuit. (Use Ohm's law)
3. What is the role of the ozone layer in protecting life on Earth?
4. If the focal length of a concave mirror is 15 cm, what is its radius of curvature?
5. Differentiate between renewable and non-renewable sources of energy with one example each.
6. State Newton's third law of motion with one everyday example.
7. Why does the sky appear blue during the day?
8. Define electric power. Write its SI unit and the formula relating it to V and I.
9. What is the difference between a 'group' and a 'period' in the modern periodic table?
10. Define a reflex action and give one example.
11. A force of 20 N moves an object through a distance of 5 m in the direction of the force. Calculate the work done.
12. Write the balanced chemical equation for photosynthesis.
13. State two main differences between alternating current (AC) and direct current (DC).
14. Define resistivity of a conductor. State its SI unit.
15. Distinguish between heredity and variation with one example each.
16. State the law of conservation of mass with a chemical equation example.
17. A concave lens has a focal length of 20 cm. Find its power.
18. What is the difference between an acid and a base in terms of ions produced in water?
19. Explain why metals are good conductors of electricity.
20. State Mendel's law of dominance with one example.
21. A current of 2 A flows through a conductor for 5 minutes. Find the total charge passed.
22. What is the function of the placenta in human reproduction?
23. Write the electron dot structure for a molecule of methane (CH₄).
24. State the two conditions necessary for combustion to occur.
25. What is meant by the term 'magnetic field line'? State one property.
26. Calculate the equivalent resistance of two resistors of 4Ω and 6Ω connected in series.
27. Define the term 'excretion'. Name the primary excretory organ in humans.
28. Why is the process of respiration considered an exothermic reaction?
29. Distinguish between a concave and a convex mirror based on image formation for a distant object.
30. State the difference between speed and velocity.

Tip: You can paste actual questions from back-of-chapter exercises for laser-focused chapter revision.

CBSE-style answer key & marking notes

Explanations and chemical/physical laws mapped to the questions above, helping you master the underlying concepts before generating a fresh paper.

• Q1: Refraction is the bending of light when it passes from one transparent medium to another due to a change in its speed. Snell's law: n₁ sin θ₁ = n₂ sin θ₂, i.e. the ratio sin i / sin r is constant for a given pair of media (the refractive index).
• Q2: Using Ohm's law, I = V / R = 5 V / 10 Ω = 0.5 A. The current through the circuit is 0.5 ampere.
• Q3: The ozone layer in the stratosphere absorbs most of the Sun's harmful ultraviolet (UV-B and UV-C) radiation, protecting living organisms from skin cancer, cataracts, damage to crops and harm to aquatic life.
• Q4: For a spherical mirror, R = 2f. So R = 2 × 15 cm = 30 cm.
• Q5: Renewable sources can be replenished naturally on a human timescale (e.g. solar energy). Non-renewable sources exist in finite reserves and exhaust with use (e.g. coal / petroleum).
• Q6: To every action there is an equal and opposite reaction. Example: when you jump off a small boat onto a jetty, the boat moves backward as you push it forward.
• Q7: Sunlight is scattered by the molecules of the atmosphere. Shorter wavelengths (blue) are scattered far more than longer wavelengths (red) — this is Rayleigh scattering — so the sky appears blue.
• Q8: Electric power is the rate at which electrical energy is consumed (or work is done) in a circuit. SI unit: watt (W). Formula: P = V × I (also P = I²R = V²/R).
• Q9: A 'group' is a vertical column (elements with similar chemical properties / same number of valence electrons). A 'period' is a horizontal row (elements with the same number of shells).
• Q10: A reflex action is a quick, automatic response to a stimulus controlled by the spinal cord (not the brain). Example: pulling the hand back on touching a hot object.
• Q11: Work done W = F × d × cos θ. Force and displacement are in the same direction (θ = 0°), so W = 20 × 5 × 1 = 100 J.
• Q12: 6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂ (in the presence of sunlight and chlorophyll).
• Q13: (i) AC reverses its direction periodically; DC flows in one direction only. (ii) AC can be stepped up/down by transformers and is used for transmission; DC is used in batteries and electronic devices.
• Q14: Resistivity (ρ) is the resistance offered by a conductor of unit length and unit cross-sectional area at a given temperature. SI unit: ohm-metre (Ω·m).
• Q15: Heredity = transmission of characters from parents to offspring (e.g. eye colour). Variation = differences seen between offspring and parents or among siblings (e.g. height differences in a family).
• Q16: Mass can neither be created nor destroyed in a chemical reaction. Example: in CaCO₃ → CaO + CO₂, the total mass of reactants equals the total mass of products.
• Q17: Power P = 100/f(cm in metres) = 100 / (−20) = −5 D. (Negative because a concave lens is divergent, and focal length is taken as negative by sign convention.)
• Q18: An acid produces H⁺ (hydrogen) ions when dissolved in water, while a base produces OH⁻ (hydroxide) ions when dissolved in water.
• Q19: Metals contain a large number of free (delocalised) electrons that can move freely through the metallic lattice, allowing them to carry electric charge easily.
• Q20: When two contrasting alleles are present together, only one (the dominant allele) expresses itself in the phenotype, masking the other (recessive) allele. Example: in pea plants, the tall (T) allele is dominant over the short (t) allele.
• Q21: Charge Q = I × t = 2 A × (5 × 60 s) = 2 × 300 = 600 coulombs.
• Q22: The placenta connects the developing embryo to the uterine wall, allowing nutrient uptake, waste elimination, and gas exchange between mother and foetus via the mother's blood.
• Q23: In CH₄, the carbon atom shares one electron pair with each of the four hydrogen atoms, giving carbon a stable octet and each hydrogen a stable duplet, forming four single C–H covalent bonds.
• Q24: A combustible substance (fuel) must be present, and there must be a supporting medium such as oxygen (or air) along with a source of heat to raise the fuel to its ignition temperature.
• Q25: A magnetic field line is a path along which a north magnetic pole would tend to move in a magnetic field. One property: field lines never intersect each other.
• Q26: In series, resistances add directly: R = R₁ + R₂ = 4Ω + 6Ω = 10Ω.
• Q27: Excretion is the biological process of removing metabolic waste products from the body. The kidneys are the primary excretory organs in humans.
• Q28: Respiration breaks down glucose in the presence of oxygen to release energy (ATP) along with carbon dioxide and water, and this energy is released to the surroundings, making it exothermic.
• Q29: A concave mirror converges light and forms a real, inverted, diminished image of a distant object at its focus, while a convex mirror diverges light and always forms a virtual, erect, diminished image regardless of object distance.
• Q30: Speed is a scalar quantity describing only how fast an object moves (distance/time), while velocity is a vector quantity describing both speed and direction of motion (displacement/time).

Tips for CBSE Preparation

• ✓Use NCERT exercise questions as your source for the most syllabus-accurate output.
• ✓Paste questions chapter by chapter to focus revision on one topic at a time.
• ✓Set difficulty to Tough or Mixed to simulate board-exam level questions.
• ✓Include previous-year questions to get questions that follow the exact CBSE marking pattern.
• ✓Use the timer to practise under exam conditions before the actual board exam.

CBSE board-year practice tests

Class 9 through 12 carry the most board-pattern weight — start with these.

• Class 9 Science practice test— NCERT chapter-wise questions
• Class 10 Social practice test— concept-based questions
• Class 11 English practice test— grammar, reading & writing
• Class 12 Business Studies practice test— concept-based questions

Frequently Asked Questions