ICSE Class 10 Science Important Questions 2027 — Physics, Chemistry and Biology
Chapter-wise ICSE Class 10 Science important questions for 2027, across the three separate Physics, Chemistry and Biology papers, with must-draw diagrams.
ICSE Class 10 Science is three separate papers — Physics, Chemistry and Biology — each an 80-mark, two-hour exam with 20 marks of internal assessment. Each paper has a compulsory Section A covering the whole syllabus and a Section B with a choice of longer questions. Below are important questions for each paper.
Science Paper 1: Physics
Force, Work, Energy and Machines
| Question | Marks |
|---|---|
| State the principle of moments. A uniform metre rule balances at the 40 cm mark when a 50 g mass hangs at the 10 cm mark. Find the mass of the rule. | 4 |
| Define mechanical advantage, velocity ratio and efficiency of a machine, and derive the relation between them. | 4 |
| A pulley system has VR = 4. An effort of 50 N lifts a load of 160 N. Find (a) MA, (b) efficiency, (c) the effort needed if the machine were ideal. | 4 |
| State the principle of conservation of energy and show that the total mechanical energy of a freely falling body stays constant. | 4 |
Light
| Question | Marks |
|---|---|
| Draw ray diagrams for a convex lens with the object (a) beyond 2F, (b) between F and 2F, (c) at F. | 5 |
| A convex lens of focal length 15 cm forms a real image 30 cm from the lens. Find the object distance and the magnification. | 3 |
| What is total internal reflection? State its two conditions and give two applications. | 3 |
| How does a convex lens work as a magnifying glass? Where must the object be placed? | 3 |
| Explain the dispersion of white light by a prism with a labelled diagram. | 4 |
Sound
| Question | Marks |
|---|---|
| What are the characteristics of sound? How do pitch and loudness depend on frequency and amplitude? | 3 |
| Distinguish natural, damped and forced vibrations. What is resonance? Give an example. | 4 |
| What conditions are needed to hear an echo? A person claps near a cliff and hears the echo after 1.5 s. Find the distance to the cliff (speed of sound 340 m/s). | 4 |
Electricity and Heat
| Question | Marks |
|---|---|
| State Ohm's law and draw the V–I graph. Resistors of 3 Ω, 4 Ω and 5 Ω are connected in parallel to a 12 V battery. Find the equivalent resistance, the total current and the current in each. | 5 |
| Derive the equivalent resistance of resistors in (a) series, (b) parallel. | 4 |
| A 1000 W iron is used for 2 hours a day. Find the energy used in 30 days and the cost at ₹5 per unit. | 3 |
| Explain how a fuse works. Why is it connected in the live wire? | 3 |
| Distinguish emf and terminal voltage. A cell of emf 2 V and internal resistance 0.5 Ω is connected to a 4.5 Ω resistor. Find the current and the terminal voltage. | 4 |
| Define specific heat capacity and latent heat of fusion. Solve a mixing problem using the principle of calorimetry. | 4 |
ICSE Science chapter-wise practice
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Start freeScience Paper 2: Chemistry
Acids, Bases and Salts
| Question | Marks |
|---|---|
| Define pH. What is the pH of (a) pure water, (b) lemon juice, (c) sodium hydroxide solution? How does pH change when an acid is added to water? | 3 |
| Write balanced equations for (a) dilute hydrochloric acid on sodium carbonate, (b) concentrated sulphuric acid on sodium chloride, (c) neutralisation of sodium hydroxide by hydrochloric acid. | 3 |
| Describe how a named soluble salt and a named insoluble salt are prepared in the laboratory. | 4 |
Organic Chemistry
| Question | Marks |
|---|---|
| Write the IUPAC names of (a) CH₃CH₂OH, (b) CH₃CHO, (c) CH₃COOH, (d) CH₃COCH₃, (e) CH₃CH₂CH₂Br. | 3 |
| What is a homologous series? Give three characteristics and the general formulae of alkanes, alkenes and alkynes. | 4 |
| Give the structural formula and one property each of ethanol and ethanoic acid. How does each react with sodium? | 4 |
| What are isomers? Draw and name two isomers of C₄H₁₀. | 3 |
| Distinguish addition and substitution reactions, with one equation for each. | 3 |
Metallurgy and Mole Concept
| Question | Marks |
|---|---|
| Describe the extraction of aluminium from alumina by electrolysis, with equations. | 5 |
| Find the number of moles and molecules in 11 g of CO₂ (C = 12, O = 16). | 3 |
| What volume of oxygen is needed for the complete combustion of 2 litres of propane (C₃H₈), all volumes at the same temperature and pressure? | 3 |
| What is an alloy? Give the composition and one use of brass, bronze and stainless steel. | 3 |
Analytical Chemistry
| Question | Marks |
|---|---|
| Using one reagent in each case, distinguish (a) dilute HCl and dilute H₂SO₄, (b) NaCl and NaNO₃ solutions, (c) MnO₂ and CuO. | 3 |
| Carbon dioxide turns lime water milky, and the milkiness disappears when excess gas is passed. Write equations for both reactions, and name a test that tells CO₂ apart from SO₂, which behaves the same way with lime water. | 3 |
| Describe the action of sodium hydroxide solution on (a) ammonium chloride (warmed), (b) iron(III) chloride solution, (c) lead nitrate solution, naming the gas or precipitate. | 3 |
CISCE revised the ICSE Chemistry syllabus for 2027, so check each topic against your current syllabus.
Science Paper 3: Biology
Cell Division and Genetics
| Question | Marks |
|---|---|
| Describe the stages of mitosis with diagrams. Why is mitosis important? | 5 |
| Explain Mendel's monohybrid cross with tall and dwarf pea plants. Draw the Punnett square and state the F1 and F2 ratios. | 5 |
| Define genotype, phenotype, homozygous, heterozygous and allele. | 3 |
| What is sex-linked inheritance? Show the inheritance of colour blindness with a cross. | 4 |
Plant Physiology
| Question | Marks |
|---|---|
| Describe photosynthesis, write its overall equation and name the factors that affect its rate. | 5 |
| What is transpiration? Give its advantages and the factors that affect its rate. | 4 |
| Explain how roots absorb water, using the terms osmosis and root pressure. | 3 |
| Name the main plant hormones and give one function of each. | 3 |
Human Physiology
| Question | Marks |
|---|---|
| Draw a labelled diagram of the human heart and describe double circulation. | 5 |
| Draw a labelled nephron and describe urine formation (filtration, reabsorption, secretion). | 5 |
| Draw a labelled human eye. Explain accommodation, and the causes and correction of myopia and hypermetropia. | 5 |
| Draw a labelled human ear and explain how it helps in hearing and balance. | 4 |
| Draw a neuron and label the cell body, dendrites, axon, myelin sheath and nerve endings. What is a synapse? | 4 |
| Distinguish (a) arteries and veins, (b) red and white blood cells, (c) blood plasma and serum. | 3 |
| Draw a labelled diagram of the human male or female reproductive system and describe the menstrual cycle. | 5 |
Population and Pollution
| Question | Marks |
|---|---|
| What are the causes of rapid population growth in India, and what measures can control it? | 3 |
| What is the greenhouse effect? Name three greenhouse gases and explain how they lead to global warming. | 3 |
Must-Draw Diagrams
| Paper | Diagrams |
|---|---|
| Physics | Circuit diagrams, lens ray diagrams, prism dispersion, pulley systems, electric motor and generator |
| Chemistry | Electrolysis set-ups, laboratory preparation of gases |
| Biology | Heart, nephron, neuron, eye, ear, reproductive systems, stages of mitosis |
Questions follow the ICSE Class 10 Physics, Chemistry and Biology syllabuses; marks per question are indicative. Check cisce.org for the latest specimen papers.
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Start freeFrequently Asked Questions
How is ICSE Science different from CBSE?
ICSE Science is three separate papers: Physics (Science Paper 1), Chemistry (Science Paper 2) and Biology (Science Paper 3). Each is an 80-mark, two-hour paper with 20 marks of internal assessment. CBSE Class 10 has a single Science paper. ICSE papers have a compulsory first section and a second section with a choice of questions.
Which ICSE Science chapters are most important?
CISCE doesn't publish chapter-wise marks, and the compulsory first section of each paper covers the whole syllabus. Chapters that often carry longer questions: in Physics, current electricity, light, machines and calorimetry; in Chemistry, mole concept, analytical chemistry, study of compounds and organic chemistry; in Biology, genetics, the circulatory, excretory and nervous systems, and photosynthesis.
Are diagrams important in ICSE Science?
Yes, especially in Biology. Practise circuit diagrams, ray diagrams for lenses, the human heart, nephron, neuron, eye, ear, the reproductive systems and the stages of cell division. ICSE examiners expect neat, large, well-labelled diagrams.
How do I score 90+ in ICSE Science?
(1) Master the diagrams by drawing them from memory. (2) Solve CISCE's specimen papers and past ICSE papers for each science. (3) In Chemistry, learn every equation with balancing and conditions. (4) In Physics, practise numericals chapter by chapter. (5) In Biology, learn definitions and differences in the words your textbook uses.