CBSE Class 10 questions and answers
Class 10 maths, science and foundational revision, organized by subject.
The CBSE label describes the intended study track, not an endorsement or a verified mapping to the latest syllabus. These are practice variations, many generated from templates and numeric inputs, not an official question bank. They remain outside search indexing until at least 100 independently reviewed questions across five chapters are available.
Questions and clear answers
01Mathematics · foundation · Editorial previewWhat is the maximum number of distinct real zeros of a quadratic polynomial?+
A polynomial of degree two has at most two distinct real zeros, although it may have fewer.
02Mathematics · foundation · Editorial previewHow do you calculate median for an odd number of observations?+
Order the data and choose the value in the central position of the sorted list.
03Physics · foundation · Editorial previewWhere do parallel incident rays meet after reflecting from a concave mirror?+
Under the paraxial approximation, rays parallel to the principal axis reflect through the principal focus.
04Biology · foundation · Editorial previewWhat is the function of the human heart?+
The heart pumps blood through the pulmonary and systemic circulatory systems.
05Mathematics · Real numbers · advanced · Editorial previewIn cbse class 10 — Real numbers: Split 12705 items between two groups in the ratio 4210:25. How many go to the first group?+
The total ratio is 4235 parts. First group = 12705 × 4210/4235 = 12630.
06Mathematics · Polynomials · foundation · Editorial previewIn cbse class 10 — Polynomials: Solve x² − 4878x + 274797 = 0.+
Factor as (x − 4821)(x − 57) = 0; x = 4821 or x = 57.
07Mathematics · Linear equations · foundation · Editorial previewIn cbse class 10 — Linear equations: Solve 17x + 30 = 7391 for x.+
Subtract 30 and divide by 17: x = 433.
08Mathematics · Triangles · intermediate · Editorial previewIn cbse class 10 — Triangles: A right triangle has perpendicular sides of 72 cm and 20 cm. Find the hypotenuse to three decimals.+
By Pythagoras, c = √(5184 + 400) ≈ 74.726 cm.
09Mathematics · Trigonometry · foundation · Editorial previewIn cbse class 10 — Trigonometry: In a right triangle, sides opposite and adjacent to angle θ are 24 cm and 48 cm. Find sin θ to 4 decimals.+
Hypotenuse = √(576 + 2304) ≈ 53.6656 cm; sin θ = 24/hypotenuse ≈ 0.4472.
10Mathematics · Statistics · advanced · Editorial previewIn cbse class 10 — Statistics: Four measurements are 2266, 8, 2271 and 13. What is their arithmetic mean?+
Sum = 4558; divide by 4 to get 1139.5.
11Mathematics · Probability · intermediate · Editorial previewIn cbse class 10 — Probability: A bag contains 2877 blue tokens and 40 red tokens. What is the probability of randomly drawing a red token?+
There are 2917 tokens, so P(red) = 40/2917 ≈ 0.0137.
12Physics · Light · foundation · Editorial previewIn cbse class 10 — Light: A thin convex lens has focal length 6 cm. An object lies 28 cm from it. Find approximate image distance using the thin-lens equation.+
With 1/f = 1/u + 1/v for positive object/image distances, v = fu/(u-f) = 6×28/22 ≈ 7.636 cm.
13Physics · Electricity · foundation · Editorial previewIn cbse class 10 — Electricity: A resistor of 13 Ω carries 6 A of current. Find the voltage.+
V = IR = 6 × 13 = 78 volts, assuming Ohm's law applies.
14Chemistry · Chemical reactions · intermediate · Editorial previewIn cbse class 10 — Chemical reactions: In a closed reaction, 4710 g of one reactant combines completely with 18 g of another. Find the total product mass.+
Conservation of mass: 4710 + 18 = 4728 g (assuming all matter is accounted for).
15Chemistry · Acids bases and salts · advanced · Editorial previewIn cbse class 10 — Acids bases and salts: A formal model solution has [H⁺] = 10^(-4) mol/L and volume 3 L. Under an ideal concentration model, find pH and moles of hydrogen ions.+
pH = 4; amount of H⁺ = 3 × 10^(-4) mol. This is a formal model; real dilute solutions require activity/water considerations.
16Physics · Motion and forces · foundation · Editorial previewIn cbse class 10 — Motion and forces: An object of mass 11 kg accelerates at 10 m/s². Find the net force.+
Newton's second law: F = ma = 11 × 10 = 110 newtons.
17Mathematics · Real numbers · intermediate · Editorial previewIn cbse class 10 — Real numbers: Split 28782 items between two groups in the ratio 1544:55. How many go to the first group?+
The total ratio is 1599 parts. First group = 28782 × 1544/1599 = 27792.
18Mathematics · Polynomials · foundation · Editorial previewIn cbse class 10 — Polynomials: Solve x² − 2183x + 60340 = 0.+
Factor as (x − 2155)(x − 28) = 0; x = 2155 or x = 28.
This is an educational practice preview. Answers and board-specific alignment are undergoing editorial review; these are not official exam questions.