CBSE Class 10 Science Question Paper with Answer Key 2026: PDF Download, Exam Analysis

The Central Board of Secondary Education has conducted the Class 10 Science exam on February 25, 2026. The exam has been conducted between 10:30 AM and 1:30 PM. The overall difficulty level was easy to moderate. Based on students' review, the difficulty level of section A, B, C was easy and D was moderate. The unofficial CBSE Class 10 Science Answer Key 2026 has been updated here shortly after the exam is concluded at 1:30 PM. Knowing the CBSE 10th Science Answer Key 2026 will enable you to understand your probable scores. You can easily match your answers with the answer key provided here. You will require at least 33% marks in each subject to pass, combining theory and internal/practical assessments as per the CBSE Class 10 Passing Marks 2026 . Continue reading the article to know the CBSE Class 10 Science Answer Key 2026.

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CBSE Class 10 Science Unofficial Answer Key 2026

The CBSE Class 10 Science exam comprises a theory paper of 80 marks and an internal assessment of 20 marks. The theory paper consists of 5 sections, from A to E, including objective, assertion-reason, short/long answer, and case-based questions. The paper generally focuses on NCERT-based content, with significant weightage on biology and application-based questions. Here we have provided the CBSE Class 10 Science Unofficial Answer Key 2026 for all sets (Set 1, 2, 3). You will find the answer key for the objective questions, i.e., Section A, from questions 1 to 20 only. The tables below are updated now:

Section A - (Biology) - Set 1 (31/2/1)

Question No.	Question (Set 1)	Answer
1	The genotype of green stemmed tomato plant is denoted by 'GG' and of purple stemmed tomato plant as two were self-pollinated to obtain Fo progeny. What will be the ratio of 'gg. Hybrid of a cross between these GG, Gg and gg in this F2 progeny?	d) 1:2:1
2	Identify the type of tropic movement that is responsible for the movement of the pollen tube towards an ovule from the following options	c) Chemotropism
3	Spirogyra, despite being a multicellular organism, still shows a simple reproductive method...	c) Asexual reproduction by breaking up of spirogyra filaments into smaller parts
4	The carbohydrates, which are not used immediately in plants, are stored in the form of 'a', which serves as an internal energy reserve. What does 'a' stand for?	a) starch
5	The following events occur during the process of photosynthesis. Choose the option that indicates the correct events	b) (ii) and (iii)
6	-	b) T5
7	TBU	TBU
8	Assertion and Reasoning	a)
9	Assertion and Reasoning	b)

Section C (Physics) - Set 1 (31/2/1)

Question No.	Question (Set 3)	Answer
30	From the following options choose the one which gives negative. magnification greater than one	a) concave mirror, nature of image - real
31	A thin beam of white light falls on a face of a glass prism and a spectrum is obtained on a screen. Which of the following options is the correct sequence of colours from top to bottom on the screen?	b)
32	Assertion and Reasoning	b)

Section A (Biology) - Set 2 (31/2/2)

Question No.	Question (Set 2)	Answer
1	Spirogyra, despite being a multicellular organism, still shows a simple reproductive method...	c) Asexual reproduction by breaking up of spirogyra filaments into smaller parts
2	The genotype of green stemmed tomato plant is denoted by 'GG' and of purple stemmed tomato plant as two were self-pollinated to obtain Fo progeny. What will be the ratio of 'gg. Hybrid of a cross between these GG, Gg and gg in this F2 progeny?	d) 1:2:1
3	Identify the type of tropic movement that is responsible for the movement of the pollen tube towards an ovule from the following options	c) Chemotropism
4	If the stomatal pore is open, it indicates which situation from the foolowing	d) The guard cells have swelled due to inflow of water
5	Which of the following limits the number of trophic levels in a food chain	c) Decrease in energy at higher levels
6	The following events occue during the process of photosynthesis...	b) (ii) and (iii)
7	-	b) T5

Section B (Chemistry) - Set 2 (31/2/2)

Question No.	Question (Set 3)	Answer
1	Tamarind is natural source of which acid?	b) tartaric acid
2	Rain water is called acid rain when its?	d) pH falls below 5.6

Section A - (Biology) - Set 3 (31/2/3)

Question No.	Question (Set 3)	Answer
1	The carbohydrates, which are not used immediately in plants, are stored in the form of 'a', which serves as an internal energy reserve. What does 'a' stand for?	a) starch
2	Spirogyra, despite being a multicellular organism, still shows a simple reproductive method...	c) Asexual reproduction by breaking up of spirogyra filaments into smaller parts
3	Identify the type of tropic movement that is responsible for the movement of the pollen tube towards an ovule from the following options	c) Chemotropism
4	The genotype of green stemmed tomato plant is denoted by 'GG' and of purple stemmed tomato plant...	d) 1:2:1
5	Select the option that represents the correct balanced equation...	d)
6	Which of the following limits the number of trophic levels in a food chain	c) Decrease in energy at higher levels
7	-	b) T5
8	Assertion and Reasoning	b)
9	Assertion and Reasoning	a)

Section B - (Chemistry) - Set 3 (31/2/3)

Question No. (Set 3)	Answer
17	c) oxalyic acid
18	b) washing soda
19	c) i and iii
20	c) X - hydrochloric acid, Y - carbon dioxide
21	c) green colour of the salt fades and the smell of buring sulphur is evolved
22	d) It changes colour due to rusting
23	c) Mg rteacts with water to produce H2 gas which helps in floating
24	a) Both Assertion and Reason are True and Reason is correct Explanation of Assertion

Section C - (Physics) - Set 3 (31/2/3)

Question No. (Set 3)	Answer
30	a) Concave Mirror, Nature of image - real
31	b) Red, Yellow, Green, Blue, Violet
32	b) (A) Both Assertion and Reason are True but Reason is not correct Explanation of Assertion

Section A (Biology) - Set 31/5/1

Question No. (Set 1)	Answer
1	c) guard cells
2	a) Pituitary Glands
3	d) Glucose Pyruvate Lactic Acid+Energy
4	c) Uterus
5	c) 44 + XY
6	b) DDT
7	b) Break down complex organic substances to simple inorganic substances.

Section B (Chemistry) - Set 31/5/1

Question No. (Set 1)	Answer
17	b) 2:1
18	d) C4 Hg and C5 H12
19	d) Al2O3
20	d)
21	c) C3H8
22	d) Hydrochloric acid and sodium hydroxide
23	c) Hydrogen
24	a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A)

Section C (Physics) - Set 31/5/1

Question No. (Set 1)	Answer
30	a) 20 cm
31	a) converging lens
32	d)

Section A (Biology) - Set 31/5/2

Question No. (Set 2)	Answer
1	c) uterus
2	d) budding
3	c) guard cells
4	d)
5	b) DDT
6	c) 44 + XY
7	c)
8	a)

Section B (Chemistry) - Set 31/5/2

Question No. (Set 2)	Answer
17	d) C 4 H 8 and C 5 H 12
18	d) Al 2 O 3
19	c) the amount of hydrogen gas evolved in less amount

CBSE Class 10 Science Passing Marks 2026

CBSE Class 10 students are required to acquire a minimum of 33% aggregate marks out of 100 in Science . This applies to both theory and internal assessment. Out of 80 in theory paper, they need at least 26 marks, and in 20-mark internal assessment, a minimum of 7 marks are required. CBSE Class 10 Science is a compulsory subject along with English, Social Science, Math and Second Language. Students have to pass all subjects, including the best five for aggregate computation.

CBSE Class 10 Grading System 2026

CBSE uses a 9-point relative grading scale for Class 10 exam 2026 board exams. CBSE will be focusing on percentile ranks among passed students rather than absolute marks only. Grades range from A1 (top performers) to E (essential repeat), with separate application to theory and internal assessments. However, for subjects of internal examination in Class 10, the assessment will be made on a five point scale, that is, A,B,C,D & E. The grades will be derived from scores in case of subjects of external examination. In case of subjects of internal assessment, they will be awarded by the schools.

CBSE Class 10 Marsheet 2026

CBSE has introduced a new draft scheme for Class 10 board exams, which will include the results of two attempted exams. The marksheet will list personal details, subject-wise performance, CGPA, marks from both attempts, internals, and the better score used for grading/ passing. CBSE will not issue any passing certificate after the first exam. The full document will be issued after the second exam by late June. However, students can access the Phase I CBSE Class 10 result 2026 via the official website, DigiLocker app/website, UMANG app, SMS, and IVRS.

CBSE Class 10 Merit Certificates 2026

CBSE will provide merit certificates to Class 10 students who will score in the top 0.1% of candidates passing each subject. Students will be eligible to get the Pass Certificate of the Board if he/ she gets a grade higher than E in all subjects of internal assessment. CBSE will provide the merit certificates only if at least 500 students pass the subject. Otherwise, no one will be awarded. Under the new two-exam policy, merit certificates will be issued only after the second exam is over.

Section A of the CBSE 10th Science question paper contains 20 multiple-choice questions, each carrying 1 mark. The question paper comprises a total of 39 questions, where internal choices will be available for a few sections. You can also check CBSE 10th Result 2026 here.