Class 10 PT I Question Paper 2025-26 Science

CBSE CLASS 10
PT I Question Paper
Session 2025-26

SCIENCE

Exam CBSE Class 10
Subject Science
Session 2025-26
Document Type PT I Question Paper

Notes · Sample Papers · Previous Year Papers · Mock Tests

.
.co s e m
em l a

as Question Paper ag
FIRST UNIT TEST
SESSION: 2025-2026
CLASS: X MAXIMUM MARKS: 40
SUBJECT: SCIENCE TIME: 1 Hour 30 Minutes
General Instructions:

m
Read the following instructions very carefully and strictly follow them:

om
(i) This question paper contains 19 questions in 6 pages. All questions are compulsory.
. co
. c e m
s
(ii) This question paper is divided into five sections – A, B, C, D and E.

e m l a
s
(iii) In Section A – Questions no. 1 to 10 are Multiple Choice (MCQ) type questions, carrying 1
mark each.
l a ag
ag
(iv) In Section B - Questions no. 11 and 12 are Very Short Answer (VSA) type questions, carrying
2 marks each.
(v) In Section C - Questions no. 13 to 16 are Short Answer (SA) type questions, carrying 3 marks
each.
(vi) In Section D - Questions no. 17 and 18 are Long Answer (LA) type questions, carrying 5
marks each.
(vii) In Section E - Questions no. 19 is a case study based question, carrying 4 marks.

m
(viii) There is no overall choice given in the question paper. However, an internal choice has

.co
been provided in few questions in all the sections except Section A.

e m
SECTION A
1. Consider the chemical equation given below:
l as 1

ag
p Al2O3 + q HCl  r AlCl3 + s H2O
In order to balance the above chemical equation, the values of p, q, r and s
respectively are:
(A) 1,6,2 and 3
(B) 1,6,3 and 2
(C) 2,6,2 and 3
(D) 2,6,3 and 2

2. Identify the correct statement(s) about the chemical reaction given below: 1
m
.co
H2S + I2  2HI + S

m
.co
(i) H2S is the oxidising agent and I2 is the reducing agent.
(ii) H2S is reduced to sulphur.
e m
e m (iii) I2 is the oxidising agent and H2S is the reducing agent.
las
las (iv) I2 is reduced to HI
ag
g
(A) Only (iii)
a (B) Both (i) and (ii)
(C) Both (iii) and (iv)
(D) Both (i) and (iv)

3. For a convex mirror, the image distance (v) = 5 cm, focal length (f) = 10 cm and 1
height of the image (hi) = 7.5 cm. The correct representation according to sign
conventions is:

om . c
c m
Page 1 of 6�
�
m . s e
se
For more Question Papers, Sample Papers, Notes & Syllabus visit
gl a
Page 1 of 6

(A) v = -5 cm, f = - 10 cm and hi = - 7.5 cm
(B) v = -5 cm, f = + 10 cm and hi = - 7.5 cm
(C) v = +5 cm, f = - 10 cm and hi = + 7.5 cm
(D) v = +5 cm, f = + 10 cm and hi = + 7.5 cm

4. Analyse the table given below: 1
Column I Column II
(a) Lens formula (i) c/v
(b) Refractive index (ii) 1/v + 1/u = 1/f
(c) Power of a lens (iii) 1/v - 1/u = 1/f
(d) Mirror Formula (iv) P = 1/f
Choose the correct option:
(A) a-i, b-ii, c-iii, d-iv
(B) a-ii, b-iii, c-iv, d-i
(C) a-iii, b-i, c-iv, d-ii
(D) a-iv, b-ii, c-ii, d-iii

5. Consider the following statements regarding the human respiratory system. Choose 1
the correct option provided below.
i. The diaphragm contracts during inhalation and relaxes during exhalation.
ii. The trachea is lined with cilia and mucus to trap dust and pathogens.
iii. Expiration is always an active process requiring muscle contraction.
(A) i and ii only
(B) i and iii only
(C) ii and iii only
(D) i, ii and iii

6. Navin sets up an experiment to study the role of enzymes in digestion of food. 1

In which test tube, the digestion of protein will occur?
(A) Test tube A as HCl will breakdown proteins into simple molecules.
(B) Test tube B as HCl will breakdown protein into simple molecules.
(C) Test tubes B as pepsinogen will breakdown protein into simple molecules.
(D) Test tube B as HCl will activate pepsinogen into pepsin for breakdown of protein
into simple molecules.

Page 2 of 6�
�

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 2 of 6

.
.co s e m
em l a

as 7.
a g of cells where maximum
In the given transverse section of the leaf identify the layer 1
photosynthesis occurs are :

m
om . co
. c e m
e m l as
l as ag
g
(A) I, II
a
(B) II, III
(C) III, IV
(D) I, IV

Question numbers 8 to 10 are Assertion(A) and Reason(R) type questions. Two statements are
given – one labelled Assertion(A) and the other labelled Reason(R). Select the correct answer
from the options (A), (B), (C) and (D) as given below.

m
.co
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of

m
the Assertion (A).

s e
B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct

l a
ag
explanation of the Assertion (A).
C. Assertion (A) is true, but Reason (R) is false.
D. Assertion (A) is false, but Reason (R) is True.

8. Assertion (A): A convex mirror forms virtual, erect & diminished image of an object. 1
Reason (R): It is used in rear view mirrors of vehicles.

9. Assertion (A): AgBr is used on photographic and X-ray film. 1

m
Reason (R): AgBr is photosensitive and changes to Ag and bromine in presence of

m .co
sunlight and undergoes decomposition reaction.

c. 10.o Assertion (A): The alveoli in the lungs are highly adapted for efficient
s e m
e m l a
gaseous 1

las exchange.
g
a surface area.
ag
Reason (R): Alveoli have a thin wall, rich blood supply, and a large

SECTION B
11. A brown substance ‘A’ on heating in air forms a black substance ‘B’. When hydrogen 2
is passed over heated ‘B’, it changes back to ‘A’.
(a) What are the names of substances ‘A’ and ‘B’?
(b) Write chemical equation for the reaction that takes place when B changes back to
‘A’.

om . c
c m
Page 3 of 6�
�
m . s e
se
For more Question Papers, Sample Papers, Notes & Syllabus visit
gl a
Page 3 of 6

12. Observe the diagram given below then explain how does opening and closing of 2
stomata take place.

�

SECTION C
13. A student focused the image of a candle flame on a white screen using a convex lens. 3
He noted down the position of the candle, screen and the lens as given below. Position
of candle = 12.0 cm, Position of convex lens = 50.0 cm, Position of the screen = 88.0
cm.
(a) What is the focal length of the convex lens?
(b) Where will the image be formed if he shifts the candle towards the
lens at a position of 31.0 cm?
(c) What will be the nature of the image formed if he further shifts the
candle towards the lens?

14. An object of height h is kept at point P in front of a mirror as shown below. The 3
height of the image produced is h'. In the diagram, F is the focus and C is the centre of
curvature.

�

(a) The object is now moved to point C, will the height of the image now produced be
less than, equal to, or greater than h'? Justify your answer.
(b) If the focal length of the mirror is 20 cm and the distance between points P and C
is 10 cm, determine the distance between the images produced when the object is kept
at P and at C.
OR
A spherical lens produces an image of an object with magnification m = - 0.25.
(a) Identify the lens.
(b) State the nature of the image formed.
(c) Calculate the object and image distances if the focal length of the lens is 20 cm.

Page 4 of 6�
�

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 4 of 6

.
.co s e m
em l a

as 15.
ag 3

m
om . co
. c e m
e m l as
s
(a) List any two observations for the above experimental set up.

l a
(b) Name the type of chemical reaction taking place.
ag
ag
(c) Write balanced chemical equation for the reaction.

16. (a) In which group of animals does the blood flow through the heart once? 3
(b) Name a group of animals that can tolerate mixing up of oxygenated and
deoxygenated blood. Mention the factor on which the body temperature of this group
depends.

SECTION D

m
c. o
17. A silvery white metal X is in the form of ribbons. Upon ignition, it burns with a 5

m
dazzling white flame to form white powder Y. When water is added to the powder Y,

s e
it partially dissolves to form a substance Z which is used as an antacid.

l a
ag
(a) What is metal X?
(b) Name the white powder Y.
(c) What is the substance Z?
(d) Write the chemical reactions that are taking place.
OR
The following diagram displays a chemical reaction. Observe carefully and answer
the questions given below.

m
m .co
m .co s e m
s e g la
g la a
a
(a) Identify the type of chemical reaction that will take place and define it.
(b) How will the colour of the salt change?
(c) Write the balanced chemical equation of the reaction that takes place.
(d) Mention one commercial use of the above salt.

om . c
c m
Page 5 of 6�
�
m . s e
se
For more Question Papers, Sample Papers, Notes & Syllabus visit
gl a
Page 5 of 6

18. (a) What are the advantages of double circulation in mammals? 5

�

(b) Identify 1,2,3,4,5 and 6 in the given diagram.

OR
(a) Why is the separation of oxygenated and deoxygenated blood in mammals
and birds necessary?
(b) How are arteries different from veins? Mention any three points of difference.
SECTION E
Questions number 19 is a case study based question. Read the following paragraph and answer
the questions that follow.
19. SECTION-E 4
Q. No. 19 is a Source /Case based question with sub-parts. Internal choice is
provided in one of the sub-part.
Under the guidance of the teacher on a sunny day, a student took a concave mirror of
large aperture in his hand and directed its reflecting surface towards the sun. After
that, he directed the light reflected by the concave mirror on a thick sheet of white
paper held close to the mirror. He observed a bright circular spot of light on the paper.
The teacher said this sharp spot of light is, in fact, the real and inverted image of the
sun and the distance between the mirror and this image is the focal length of this
concave mirror.

(a) Give the meaning of the term, ‘Principal focus’ of a concave mirror.
(b) If the distance between the pole and focus of a concave mirror is 12 cm, find the
radius of curvature of the mirror.
(c) List two properties of the image formed due to a concave mirror of focal length
15 cm in each of the following cases, if the object distance is-
(i) 20 cm (ii) 10 cm
OR
(c) An object 2cm high is placed at a distance of 16cm from a concave mirror,
which produces 3cm high inverted image. Find the position of the image.

Page 6 of 6�
�

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 6 of 6