Important means useful for preparation—not guaranteed to appear. The questions below are original practice items built around major areas in the current Class 10 Science syllabus. They are not official JKBOSE questions and are not presented as previous-year questions.
Use the current syllabus guide and official PDF to confirm your applicable course. Attempt each question before opening the answer guidance.
Physics practice
1. Concave-mirror numerical
Question: An object is placed 30 cm in front of a concave mirror with focal length 15 cm. Using the Cartesian sign convention, find the image distance and state the nature of the image.
Solution: For a concave mirror, u = -30 cm and f = -15 cm. Using 1/f = 1/v + 1/u:
1/v = 1/f - 1/u = -1/15 + 1/30 = -1/30, so v = -30 cm. The negative image distance means the image forms in front of the mirror. It is real, inverted and the same size as the object.
2. Lens power
Question: A corrective lens has focal length -0.50 m. Calculate its power and identify the lens type.
Solution: P = 1/f (in metres) = 1/(-0.50) = -2 dioptres. Negative power indicates a concave or diverging lens.
3. Series-circuit reasoning
Question: Two resistors of 4 Ω and 6 Ω are connected in series across a 10 V source. Find total resistance and current.
Solution: In series, R = 4 + 6 = 10 Ω. By Ohm's law, I = V/R = 10/10 = 1 A. The same current flows through both resistors.
4. Magnetic field explanation
Question: Explain how you would determine the direction of the magnetic field around a straight current-carrying conductor.
Answer guidance: State the right-hand thumb rule: hold the conductor in the right hand with the thumb pointing in the direction of conventional current; the curled fingers show the direction of the circular magnetic-field lines.
Chemistry practice
5. Balance and classify
Question: Balance Fe + H₂O (steam) → Fe₃O₄ + H₂ and name the reaction type most directly illustrated.
Solution: 3Fe + 4H₂O → Fe₃O₄ + 4H₂. Iron displaces hydrogen from steam, so it is a displacement reaction; it also involves oxidation and reduction.
6. pH and dilution
Question: What happens to the pH of an acidic solution when it is diluted with water? Does dilution make it basic?
Answer guidance: The hydrogen-ion concentration decreases, so the pH rises towards 7. Ordinary dilution does not by itself turn the acid into a base; the solution remains acidic while pH stays below 7.
7. Reactivity reasoning
Question: Why can zinc displace copper from copper sulphate solution, while copper cannot displace zinc from zinc sulphate solution?
Answer guidance: Zinc is above copper in the reactivity series and loses electrons more readily. A more reactive metal can displace a less reactive metal from its salt solution.
8. Soap in hard water
Question: Why does soap form scum in hard water, and why are detergents often more effective there?
Answer guidance: Calcium and magnesium ions form insoluble salts with soap, producing scum and reducing lather. Many detergents do not form the same insoluble precipitates with these ions.
Biology practice
9. Transport in plants
Question: Distinguish the roles of xylem and phloem.
Answer guidance: Xylem mainly transports water and dissolved minerals from roots upward. Phloem transports prepared food, chiefly sugars, from source tissues to tissues that use or store it; movement can occur in different directions depending on source and sink.
10. Reflex action
Question: Why is a reflex action faster than a voluntary response? Outline a reflex arc.
Answer guidance: A reflex uses a rapid neural pathway that can be coordinated through the spinal cord before conscious processing. A basic arc is receptor → sensory neuron → relay neuron in the spinal cord → motor neuron → effector.
11. Monohybrid cross
Question: If T (tall) is dominant over t (dwarf), what genotype and phenotype ratios are expected from Tt × Tt?
Solution: The genotypes are TT, Tt, Tt and tt, giving a 1:2:1 genotype ratio. The phenotype ratio is 3 tall : 1 dwarf, assuming complete dominance.
12. Food-chain energy
Question: Why are food chains generally limited in length?
Answer guidance: Only a fraction of energy at one trophic level becomes available to the next; much is used in life processes and lost as heat. Progressively less usable energy remains at higher levels.
Long-answer prompts for written practice
- Draw two standard rays used to locate an image formed by a convex lens and explain what each ray does.
- Compare series and parallel combinations of resistors and give one practical reason household appliances are connected in parallel.
- Explain corrosion and describe two methods used to reduce it.
- Describe the path of water from soil to leaves and connect it with transpiration.
- Explain the difference between inherited and acquired traits with one example of each.
How to review this set
- Redo every numerical without looking at the substitution.
- Check units and sign conventions separately from the final value.
- Balance equations atom by atom and identify evidence for the reaction type.
- Practise Biology answers with labelled diagrams where the topic requires one.
- Ask a teacher to review long answers for scientific language and missing steps.
Continue with the existing spherical-mirrors concept guide, then use verified model papers for broader practice. Students who need a live routine can review the Jhelum Alpha Class 10 programme.
Sources and verification
- Official JKBOSE Class 10 syllabus - topic relevance
- JKBOSE official government website - current syllabus and notices