Class 10 CBSE Science Answer Key 2025 (OUT): Set-wise unofficial keys PDF download
For the exam held on February 20, Class 10 CBSE Science Answer Key 2025 has been provided here. The answer key is unofficial and given for all set codes.
Class 10 CBSE Science Answer Key 2025:Students can obtain answer keys for CBSE Class 10 Science (Subject Code: 086) held today,February 20, 2025from 10:30 am to 1:30 pm by our experts. Students can find unofficial answer key solutions for Class 10 CBSE Science comprising a of total 39 questions bifurcated into Sections A, B, C, D, and E here. Students on this page can access answers for Section A consisting of 20 objective-type questions carrying 1 mark each and estimate their scores in the section. The marking of other sections composed of short and long answer-type questions depends on the student’s way of presenting the answers. Therefore, answers to such questions will not be added. Below, you will find a comprehensive table that outlines the answers according to the respective question set, facilitating easy reference for students and educators to evaluate performance.
Also Read |Class 10 CBSE Result Expected Release Date 2025
Class 10 CBSE Science Answer Key 2025 forQP Code (31/4/1)
For Set 4 of the CBSE Class 10 Science examination, we have provided the unofficial answer key for the year 2025. This answer key includes solutions for Questions 1 to 20, each carrying a weight of 1 mark.
Section A - Multiple Choice Questions
Question No. | Question (Set 4) | Answer for QP code (31/4/1) |
| 1 | In which of the following situations a chemical reaction does not occur? | Melting of Glaciers |
| 2 | In order to prepare dry hydrogen chloride gas in humid atmosphere the gas produced is passed through a guard tube (drying tube) which contain? | Calcium Chloride |
| 3 | The property by virtue of which a solid material can be drawn into thin wires is called | Ductility |
| 4 | Select from the following a hydrocarbon having one C-C bond and one C--- bond: | Cyclohexane |
| 5 | The essential element taken up from the soil by the plants to synthesize proteins is: | Nitrogen |
| 6 | Select true statements about lymph from the following: a. Lymph vessels carry ymph through the body and finally open into larger arteries b. Lymph contains some amount of plasma, proteins and blood cells. c. Lymph contains some amount of plasma, proteins and red blood cells. d. Lymph vessels carry lymph through the body and finally open into larger veins. | C and D |
| 7 | Plants like Rose and Banana have lost the capacity to produce _____ | Seeds |
| 8 | In a bisexual flower the male gametes are present in the _____ | Anther |
| 9 | When a pure tall-tea plant i crossed with a pure dwarf pea plant, the percentage of tall pea plants in F1and F2generation pea plants will be respectively: | 100%; 75% |
| 10 | To get an image of magnification -1 on a screen using a length of focal length 20 cm, the object distance must be | 80 cm |
| 11 | An optical device 'X' is placed obliquely in the path of a narrow parallel beam of light. If the emergent beam gets displaced laterally, the device 'X' is: | Convex lens |
| 12 | A piece of wire of resistance 'R' is cut length-wise into three identical parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R', then the value of R/R' is: | 1/9 |
| 13 | An electric bulb is rated 220V: 11W. The resistance of its filament when it glows with a power supply of 220 V is: | 4400 Ω |
| 14 | The minimum number of identical bulbs of rating 4V; 6W, that can work safely with desired brightness, when connected in a series with a 240 V mains supply is: | 60 |
| 15 | In the food chain given below. Select the most efficient food chain in terms of energy: Grass → Grass hopper →Frog →Snake Plants → Deer → Lion Plants → Man Phytoplankton → Zooplankton →Small Fish →Big Fish | Grass → Grass hopper →Frog →Snake |
| 16 | Which one of the following gets biomagnified at different levels in a food chain? | DDT |
| 17 | Assertion (A): In large animals, oxygen can reach different parts of the animal's body easily. Reason (R): Respiratory pigments take up oxygen from the air and carry it to body tissues. | Both (A) and (R) are true and (R) is the explanation of (A). |
| 18 | Assertion (A): Concentrated nitric acid is diluted by adding water slowly to acid with constant stirring. Reason (R): Concentrated nitric acid is easily soluble in water. | Assertion (A) is true, but Reason (R) is false |
| 19 | Assertion (A): In reptiles, the temperature at which the fertilized eggs are kept decides the sex of the offspring Reason (R): Sex is not genetically determined in some animals. | Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of assertion |
| 20 | Assertion (A): When ciliary muscles contract, eye lens becomes thin. Reason (R): Ciliary Muscles control the power of the eye lens. | Assertion (A) is false but Reason (R) is true |
Class 10 CBSE Science Answer Key 2025 forQP Code (31/5/1)
For Set 1 of the CBSE Class 10 Science 2025 examination, we have provided the unofficial answer key. This answer key includes solutions for Questions 1 to 20, each carrying a weight of 1 mark.
Section A - Multiple Choice Questions
Question No. | Question (Set 1) | Answer for QP code (31/5/1) |
| 1 | The main observations while performing the experiment of burning magnesium ribbon in air are: (i) Magnesium ribbon burns with a dazzling white flame. (ii) A white powder is formed (iii) Magnesium ribbon vapourises (iv) Aqueous solution of the white powder turns blue litmus to red | i and ii |
| 2 | A metal M, displaces iron from an aqueous solution of ferrous sulfate but fails to do so in case of aqueous solution of aluminum suphate. The metal M is | Zinc |
| 3 | A common feature observed in the crystals of washing soda, copper sulfate, gypsum, and ferrous sulphate is that all | have fixed number of molecules of water of crystallisation in one formula unit of these salts |
| 4 | A metal 'X' on treatment with sodium hydroxide liberates a gas 'G'. It also liberates the same gas, 'G' on treatment with dilute sulphuric acid. | Zinc and hydrogen |
| 5 | The values of a,b,c and d in the following balanced chemical equation are respectively: a Pb (NO3)2→bPbO + cNO2+ dO2 | 1,1,2,1 |
| 6 | During electrolytic refining of copper, the anode, the cathode, and the electrolyte used respectively are | Impure copper, pure copper, acidified copper sulphate solution |
| 7 | If we make carbon skeleton with four carbon atoms, the two different possible skeletons will be | C-C-C-C, C-C// C |
| 8 | Listed below are the steps of nutrition in Ameoba. Select the correct sequence of the steps. Diffusion of simple nutrients into cytoplasm (i) Food vacuole formation (ii) Formation of finger-like temporary extensions of cell surface (iii) Complex substances broken to simpler ones (iv) Undigested material thrown out of the cell surface | iii, ii, iv, i, v |
| 9 | Which among the following is not a neural action controlled by the part of human brain labeled 'X' in the figure above? | Hunger |
| 10 | The modes of reproduction in Spirogyra and Planaria respectively are | Fragmentation and regeneration |
| 11 | The plant hormones promoting rapid cell division in seeds and wilting of leaves respectively are | Cytokinins and Abscisic acid |
| 12 | In aerobic respiration, the steps are: breakdown of glucose to pyruvate and its further conversion to carbon dioxide. Both processes respectively occur in | Cytoplasm and Mitochondria |
| 13 | In order to obtain large images of teeth of patients, the dentist holds the concave mirror in such a manner that the teeth are positioned | Between Pole and Focus of the mirror |
| 14 | The possible way to restore clear vision of those people whose eyeball has elongated is the use of suitable | Convex lens |
| 15 | The examples of natural and manmade (artificial) ecosystems are respectively | Forests and pons |
| 16 | Human activities that are affecting the environment are | Excessive use of disposable cups and plates |
| 17 | Assertion (A): Silver chloride turns grey in sunlight Reason (R): Decomposition of Silver chloride into silver and chlorine takes place by sunlight | Both Assertion and Reason are correct and Reason is the correct explanation for Assertion |
| 18 | Assertion (A): The embryo gets nutrition from the mothers blood with the help of a special tissue called the placenta. Reason (R): Placenta is a disc which is embedded in the uterine wall. | Both the Assertion and Reason are correct, and the reason correctly explains the assertion |
| 19 | Assertion (A): The pattern of a magnetic field of a solenoid carrying a current is similar to that of a bar magnet. Reason (R): The pattern of a magnetic field around a current carrying conductor is independent of the shape of the conductor. | Both Assertion and Reason are correct and Reason is the correct explanation for Assertion |
| 20 | Assertion (A): All organisms can make organic compounds like sugar and starch from inorganic substances using radiant energy of the sun. Reason (R): The organisms that can produce food by photosynthesis are called producers. | Both Assertion and Reason are correct, and R is correct explanation of the assertion. |
Class 10 CBSE Science Exam Analysis 2025 Link
Students can tap on the link to access the Class 10 CBSE Science exam analysis 2025 and review their exam performance.
CBSE Class 10 Subject-Wise Answer Key 2025 |
| Subject | Links |
| All Subjects | Class 10 CBSE Answer Key 2025 |
| English | Class 10 CBSE English Answer Key 2025 |
| Social | Class 10 CBSE Social Answer Key 2025 |
| Hindi Course A | Class 10 CBSE Hindi Course A Answer Key 2025 |
| Hindi Course B | Class 10 CBSE Hindi Course B Answer Key 2025 |
| Mathematics | Class 10 CBSE Mathematics Answer Key 2025 |
| Information Technology | Class 10 CBSE Information Technology Answer Key 2025 |
| Computer Applications | Class 10 CBSE Computer Applications Answer Key 2025 |
CBSE Class 10 Toughest Easiest Subject 2025 |
| Parameters | Link |
| Toughest | Toughest Subject in CBSE Class 10 Exams 2025 |
| Easiest | Easiest Subject in CBSE Class 10 Exams 2025 |
Stay tuned to the LIVE blog for more updates on Class 10 CBSE Science Answer Key 2025.
Class 10 CBSE Science Answer Key 2025 Live Updates
Feb 20, 2025 02:00 PM IST
Use of Class 10 CBSE Science Answer Key 2025
Students through Class 10 CBSE Science Answer Key 2025 can predict their probable scores across all five sections.
Feb 20, 2025 01:45 PM IST
When will Class 10 CBSE Science Answer Key 2025 be Released?
Candidates may refer to the unofficial CBSE 10th Science 2025, which will be provided here soon. The answers will be available for multiple-choice type questions since remaining are based on the writing style of candidates.
Feb 20, 2025 01:30 PM IST
Class 10 CBSE Science Answer Key 2025: Exam Concluded, Examiners Collecting Answer Sheets
Today at 1:30 pm, Class 10 CBSE Science 2025 exam has been concluded. By the time student's answer sheets are being collected, our experts will be updating you with the unofficial answer keys anytime soon across all sets.
Feb 20, 2025 01:10 PM IST
CBSE Class 10 Science Answer Key 2025: Section E Weightage
Section E consists of 3 source-based/case-based units of assessment of 04 marks each with sub-parts.
Feb 20, 2025 12:50 PM IST
Class 10 CBSE Science Answer Key 2025: Section D Weightage
Section D of Class 10 CBSE Science Answer Key 2025 consists of 3 Long Answer type questions carrying 05 marks each. Answers to these questions should be in the range of 80 to 120 words.
Feb 20, 2025 12:30 PM IST
Class 10 CBSE Science Answer Key 2025: Section C Weightage
Section C consists of 7 Short Answer type questions carrying 03 marks each. Answers to these questions should be in the range of 50 to 80 words.
Feb 20, 2025 12:10 PM IST
CBSE Class 10 Science Answer Key 2025: Section B Weightage
Section B of CBSE Class 10 Science 2025 exam consists of 6 very short questions carrying 2 marks each. Answers to these questions should be in the range of 30 to 50 words.
Feb 20, 2025 11:50 AM IST
Class 10 CBSE Science Answer Key 2025: Section A Weightage
Section A of Class 10 CBSE Science 2025 exam consists of 20 objective-type questions carrying 1 mark each.
Feb 20, 2025 11:30 AM IST
Class 10 CBSE Science Answer Key 2025: Does the paper have internal choice?
Yes, an internal choice is provided in some questions of Class 10 CBSE Science 2025 examination. A student is expected to attempt only one of these questions.
Feb 20, 2025 11:10 AM IST
CBSE Class 10 Science Answer Key 2025: Are All Questions Compulsory?
Yes, all questions are compulsory to answer in CBSE Class 10 Science 2025 exam.
Feb 20, 2025 10:50 AM IST
CBSE Class 10 Science Answer Key 2025: Exam Begins
The CBSE Class 10 Science 2025 examination has begun at 10:30 pm. The total duration of the paper is 3 hours.
Feb 20, 2025 10:30 AM IST
CBSE Class 10 Science Answer Key 2025: Exam Started
The CBSE Class 10 Science 2025 exam has begun at 10:30 am. Stay updated on this page for all the related details.
Feb 20, 2025 10:10 AM IST
CBSE Class 10 Science Answer Key 2025: Most Repeated Question 9
The reaction of metal X with Fe2O3 is highly exothermic and is used to join railway tracks. Identify metal X. Write the chemical equation for the reaction.
Feb 20, 2025 09:50 AM IST
Class 10 CBSE Science Answer Key 2025: Most Repeated Question 8
Which of the following listed metals can displace zinc from its salt solution? Give reason for your answer with a chemical equation:
Copper, Lead, Magnesium, Silver
Feb 20, 2025 09:30 AM IST
Class 10 CBSE Science 2025 Answer Key: Most Repeated Question 7
In electrolysis of water, why is the volume of gas collected over one electrode double that of gas collected over the other electrode?
Feb 20, 2025 09:15 AM IST
Class 10 CBSE Science Answer Key 2025: Most Repeated Question 6
Two bulbs of 100 W and 40 W are connected in series.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) 1A
Feb 20, 2025 09:00 AM IST
CBSE 10th Science Answer Key 2025: Most Repeated Question 5
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
Feb 20, 2025 08:30 AM IST
Class 10 CBSE Science Answer Key 2025: Most Repeated Question 4
Assertion (A): Alloys are commonly used in electrical heating devices like electric iron and heater.
Reason (R): Resistivity of an alloy is generally higher than that of its constituent metals but the alloys have low melting points then their constituent metals.
(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Feb 20, 2025 08:15 AM IST
CBSE 10th Science Answer Key 2025: Most Repeated Question 3
Assertion (A) : The metals and alloys are good conductors of electricity.
Reason (R): Bronze is an alloy of copper and tin and it is not a good conductor of electricity.
(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Feb 20, 2025 08:00 AM IST
Class 10 CBSE Science Answer Key 2025: Most Repeated Question 2
When an object is kept within the focus of a concave mirror, an enlarged image is formed behind the mirror. This image is
(a) real
(b) inverted
(c) virtual and inverted
(d) virtual and erect
Feb 20, 2025 07:45 AM IST
CBSE Class 10 Science Answer Key 2025: Most Repeated Question 1
Here we are providing the most repeated questions of CBSE Class 10th for last-minute revision of students.
The laws of reflection hold true for:
(a) plane mirrors only
(b) concave mirrors only
(c) convex mirrors only
(d) all reflecting surfaces
Feb 20, 2025 07:30 AM IST
Class 10 CBSE Science Answer Key 2025: Exam Date
Class 10 CBSE Science Answer Key 2025: When will the exam held?
For Science (Subject Code: 086), Class 10th exam will be conducted by CBSE today on February 20, 2025.