JKBOSE Class 10th 2026 Science Solved Paper

Note: The below solutions have been prepared in concise language to suit my Govt school children. Plus the answers have been added to respective units wherever necessary.

JKBOSE Class 10th 2026 BiAnnual Private Science Solved Paper

JKBOSE Class 10th 2025 Bi-Annual Private Science Solved Paper

SECTION-A

Note:- Q. No.'s 1 to 15 are Very Short Answer Type Questions carrying 1 mark each.

1. The amount of light that is entering the eye is controlled by

(a) Pupil (b) Iris (c) Cornea (d) Eyelids

Ans: (a) Pupil

2. A person is wearing spectacle with a concave lens of suitable focal length. What kind of defect of vision is he having.

(a) Myopia (b) Hypermetropia (c) Presbyopia (d) Both (b) and (c)

Ans: (a) Myopia

3. Commercial unit of energy is

(a) V (b) W (c) J (d) kWh

Ans: (d) kWh

4. When a current is passed through a resistor, the heat produced in it is:

(a) Directly proportional to the square of current (b) Directly proportional to resistance for a given resistor

Ans: (d) All the above

5. The device used for producing electric current is called a

(a) Generator (b) Galvanometer (c) Ammeter (d) Motor

Ans: (a) Generator

6. When an iron nail is dipped in the solution of copper sulphate, the colour changes into

(a) Blue (b) Green (C) Light green (d) Brown

Ans: (C) Light green

7. The carbon atom has a Covalency of

(a) 2 (b) 1 (c) 6 (d) 4

Ans: (d) 4

8. Which of the following methods is suitable for preventing an iron pan from rusting?

(a) Applying grease (b) Applying paint (c) Applying a coating of zinc (d) All of the above

Ans: (c) Applying a coating of zinc

9. Food cans are coated with tin and not with zinc because

(a) Zinc is costlier than tin (b) Zine has a higher melting point than tin (c) Zinc is more reactive than tin (d) Zinc is less reactive than tin

Ans: (c) Zinc is more reactive than tin

10. A solution turns red litmus blue; its pH is likely to be

(a) 1 (b) 4 (c) 5 (d) 10

Ans: (d) 10

11 Which one of the following types of medicines is used for treating indigestion?

(a) Antacid (b) Analgesic (c) Antibiotics (d) Antiseptic

Ans: (a) Antacid

12. Thyroxine is produced by

(a) Pancreas (b) Pituitary gland (c) Adrenal glands (d) Thyroid gland

Ans: (d) Thyroid gland

13. Which of the following is a non-biodegradable waste?

(a) Vegetable peels (b) Paper straw (c) Polythene bags (d) Used tea bags

Ans: (c) Polythene bags

14. The problem caused due to ozone hole is

(a) Earthquakes (b) Chemical pollution (c) Acid rain (d) Damage due to UV radiation

Ans: (d) Damage due to UV radiation

15. The male sex chromosomes are expressed by

(a) XX (b) YY (c) XY (d) None

Ans: (c) XY

Notes From Q No's 16 to 18 two statements (Assertion-A and Reason-R) are given. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below

Codes:

(a) A and R are true and R is the correct explanation of A.

(b) Both A and R are true but R is not the correct explanation of A.

(c) A is true but R is false.

(d) A is false but R is true.

16. Assertion(A): When a current carrying conductor is placed in a magnetic field, it experiences a force

Reason (R) The force acting on a current carrying conductor is only due to external magnetic field.

Ans: (a) A and R are true and R is the correct explanation of A.

17. Assertion (A): Different metals have different reactivities with water and dilute acids.

Reason (R) Reactivity of a metal depends on its position in the reactivity series.

Ans: (a) A and R are true and R is the correct explanation of A.

18. Assertion (A) Autotrophs are also called as transducers

Reason (R): They change one form of energy into another.

Ans: (a) A and R are true and R is the correct explanation of A.

SECTION-B

Note: There will be Ten Questions in this section (Q. No's 19 to 28) cach carrying 2 marks.

19 State Ohm's law.

Ans: Ohms law was given by Simon Ohm. It shows relation between Potential (V) across the conductor with Current (I) through it.
Ohms law states that Current flowing in conductor is directly proportional to Potential difference across its ends.
I.e , V ∝ I
V = I × R
Where R is the resistance i.e, Opposition to flow of current.

20 On what factors does the resistance of a conductor depend?

Ans: The resistance depends on following factors:
1. The resistance increases with increase in length of conductor.
2. The resistance decreases with increase in area of cross section
3. Different materials have different resistance.
4. The resistance increases with increase in temperature.

21 Name two safety measures commonly used in electric circuits and appliances.

Ans: The safety measures commonly used in electric circuits and appliances are Electric fuse, MCB, Earth wire etc.

22 Balance the following chemical equations

(1) Na + O2 → Na₂O

Ans: 4Na + 02-à 2Na2O

(ii) CuO + H₂→ Cu + H₂O

Ans: CuO + H₂→ Cu + H₂O

23. What is Hydrogenation?

Ans: Hydrogenation means addition of hydrogen to a chemical compound.
Hydrogenation converts unsaturated hydrocarbons into saturated hydrocarbons.
Example;
CH2 = CH2 + H2 ______> CH3 - CH3
In Industries, it is used to convert oils into ghee.

24. Define the terms (i)Mineral (ii) Ore

Ans: Mineral: The compounds of elements along with impurities occuring in earths crust are called minerals.

Ore: An Ore is mineral from which the element is extracted.

25. State two ways to prevent the rusting of Iron

Ans: The rusting of Iron can be prevented by Galvanizing, Painting, Oiling, Greasing, Alloying etc.

26 What is the role of acid in our Stomach?

Ans: The acid present in stomach is HCl.
The acid makes food acidic, activates enzymes and kills microbes.

27 Draw the structure of Neuron.

Ans:

Discuss the structure of Neuron class 10th

28 State two advantages of sexual reproduction over asexual reproduction.

Ans: Sexual reproduction helps in new combination of genes. This helps organisms to adopt to changes in environment.

SECTION-C

Note: In this section from Q.No's 29 to 37, there will be Nine Questions with internal choice carrying 3 marks each.

29. Find the focal length of a lens of power -2.0 D. What type of lens is this?

Ans: Given; P = - 2.0

We Know P = 1/F

Or F = 1/P

F = 1/-2

F = - 0.5 m or - 50 cm

Negative sign means the lens is Concave.

Define: (I) Reflection of light. (ii) Principal focus

Ans: (I) Reflection of light : The bouncing back of rays of light when they falls on surface is called as reflection of light.
Reflection is smooth on plane polished surface or diffused on uneven surface.

Principal Focus: The principal focus of a concave mirror is a point on principal axis at which all the light rays parallel to it meet after reflection.

30 Why do stars twinkle?

Ans: The stars twinkle because of atmospheric refraction. As the light of stars enter earth's atmosphere, It bends due to increase in density of air.
When light is refracted towards us, stars appear brighter. When light refracted away from us, the stars appear dim.

What is meant by power of Accommodation?

Ans: power of accommodation means the adjustment of the focal length by our eye lens according to the object distance.

31. State Fleming's left hand rule

Ans: Flemings left hand rule states that if we stretch the thumb, fore finger and middle finger of our left hand in such a way that they are mutually perpendicular to each other like X, Y and Z axis of a graph.
The forefinger represents points towards magnetic field, the middle finger points towards direction of current, then thumb points towards direction of motion of the conductor.

What precautions should be taken to avoid the overloading of domestic circuit?

Ans: Following precautions should be taken to avoid the overloading of domestic electric circuits:
1. Wires of appropriate power rating and good insulation should be used.
2. There should be separate circuit for heating appliances.
3. Fuse or MCB should be installed.

32 Define displacement reaction with examples

Ans: The reaction in which one element takes place of another in a compound is called displacement reaction.
In a Displacement reaction, a more reactive element displaces a less reactive element.
Example of displacement reaction:
CuSO4 + Zn ----------> ZnSO4 + Cu

Define combination reaction with examples.

Ans: A reaction in which two or more substances, elements or compounds combine to form single substance is called combination reaction.
Examples of combination reaction:

CaO + CO2 ----------> CaCO3

33. Write down the uses of washing soda

Ans: Washing Soda is Na2CO3.

Its uses are:
1. It is used to make glass
2. It is used to make soap
3. It is used to soften hard water.

Why do acids not show acidic behaviour in the absence of water?

Ans: Acid reacts with water to form hydrogen ions (H+ ions) due to which it shows acidic behaviour.
However in absence of water, acids do not dissociate to form Hydrogen ions.

34 Why are some patients of diabetes treated by giving injections of insulin?

Ans: The diabetic patients are not able to secrete insulin to regulate blood sugar.

Hence they are given insulin injections which helps them to lower blood sugar level.

What are plant hormones? Name two plant hormones and state one function of each.

Ans: Plant Hormones are chemical substances produced in plants which help in control and coordination in plants

They are plant growth regulators. They include:

Auxins: They are found in shoot apex and young leaves.

They help in cell division and cell elongation. E.g. IAA, IBA

II. Gibberlins: They help in cell elongation and cell differentiation. E.g GA2, GA3

III. Cytokinins: They are found in endosperms and roots.

They help in cell division, cell elongation and breaking of dormancy.

IV. Abscisic acid: It acts as growth inhibitor.

It helps in promotion of dormancy, ageing of leaves.

35. How does binary fission differ from multiple fission?

Ans:

Binary Fission	Multiple Fission
The parent cell divides into two daughter cells	The parent cell divides into many daughter cells
Cytoplasm divides after every nuclear division	Cytoplasm does not divide after every nuclear division
Normally takes place in favourable conditions	Can take place in unfavourable conditions

What are different methods of contraception.

Ans: contraception means prevention of fusion of gametes.
The different methods of contraception are:
I. Natural: It can be done by avoiding intercourse from 10th to 17th day of mensuration cycle.
II. Barrier method: Use of barriers such as condom, copper T
III. Oral: Use of medicine which prevent fertlization.
IV. Surgical: It includes vasectomy and tubectomy.

36. Explain sex determination with XX-XY mechanism

Ans: The sex of child is determined by sex chromosomes. Males have XY chromosomes where as Females have XX chromosomes.
If the sperm with X chromosome fertilizes egg, The child will be female.
If the sperm with Y chromosome fertilizes egg, The child will be Male

What factors could lead to the rise of new species.

Ans: The factors that could lead to rise of new species are:
1. Isolation: When individuals of particular species are isolated geographically or reproductive. This leads to formation of new species.
2. Mutation: Mutation in genes may lead to formation of new species.
3. Genetic drift.
4. Natural selection.

37 What is Ozone? How does it affect any ecosystem?

Ans: Ozone is a molecule of oxygen (O3). It forms a layer in stratosphere and blocks Ultraviolet rays of sun from reaching earth. The Ultraviolet rays will kill living organisms by causing mutations. These rays can cause skin cancer, cataracts, and will destroy ecosystems

So Ozone is vital for all ecosystems on Earth because it protects the environment from the harmful effects of UV radiation.

Differentiate between Food Chains and Food Webs.

Ans:

Food Chain	Food Web
It is sequence of Interlinked organisms who eat each other	It is interconnected network of many food chains
Each step represents a trophic level	It provides alternate pathways

SECTION-D

Note: In this section from Q.No's 38 to 40, there will be Three Long Answer Type Questions each carrying 5 marks

38 Define spherical mirrors. Draw and Discuss the nature, position and size of image formed in case of concave mirror when object is placed at C (Centre of Curvature)

Ans: Spherical mirror is the part of sphere with curved reflecting surface. They are of two types: Concave and Convex.

Object at Centre of Curvature (C): The image is also formed at centre of curvature (C). The image is of same size, Real amd inverted.

(i) Define power of lens. State its SI units.

(ii) A doctor has prescribed a corrective lens of power +1.5D. Find the focal length of lens and nature of the lens.

Ans: (i) The Power of lens (P) is the ability of lens to converge or diverge the rays of light.
Lesser the focal length of lens, the more it converges or diverges the light. i.e,
P = 1/F
Its SI unit is dioptre, 1 dioptre means the power of lens whose focal length is 1 metres.
Power of Convex lens is Positive and power of Concave lens is negative.

(ii) Given;P = + 1.5 D

We Know that; P = 1/F

Or F = 1/P

F = 1/1.5

F = 0.67 m or 67 cm

+ve sign shows the lens is convex which is converging lens.

39. With the help of diagram, explain the cleansing action of soaps, Distinguish between soaps and detergents.

Ans: Soaps are sodium or potassium salts of fatty acids. A molecule of soap contains two parts;
i. Hydrophobic long chain hydrocarbon
ii. Hydrophilic Polar group.

Mechanism of Action: In water, the soap molecule dissociates and hydrocarbon part sticks with oils and dirt. The Polar group attaches to water. Thus micelles are formed which are washed away by water.

Soaps	Detergents
Soaps are sodium or Potassium salts of long chain fatty acids	Detergents are Ammonium or Sulphonate salts of long chain fatty acids
Soaps don’t work in hard water	Detergents work in hard water

Distinguish between Ethanol and Ethanoic acid on the basis of their properties.

Ans: Ethanol is basic having pleasant smell where as ethanoic acid is acidic having vinegar smell.
Ethanol has no action on litmus paper, Ethanoic acid turns blue litmus red.
Ethanol doesnt react with sodium bicarbonate, Ethanoic acid reacts with sodium bicarbonate.

40. Define Nutrition. Distinguish between autotrophic nutrition and heterotrophic nutrition.

Ans: Nutrition means intake of food and its utilization by body.
Nutrition is of two types; Autotrophic nutrition and Heterotrophic Nutrition

Autotrophic Nutrition	Heterotrophic Nutrition
In this type of Nutrition, organisms prepare their own food	In this type of nutrition, Organisms depend on others for food
It is of two types: Photoautotrophic and Chemoautotrophic	It is of many types: Holozoic, Saprotrophic, Parasitic
It includes green plants, blue green algae, euglena, some bacteria	It includes animals, non-green plants, fungi, some bacteria

Describe the transport of Water and Food in plants.

Ans: Transport of Water: Water and minerals are transported in plants through xylem.
The process is called ascent of sap.
The sap is absorbed by root hairs by osmosis. It is then transported into cortex cells and xylem.
The sap then moves up the plant by transpiration pull, cohesion and adhesion.

Transport of Food: The food is made in leaves of plants by the process of photosynthesis.
The food is then transported to other parts of plant through phloem and the process is called translocation.