General Instructions
1. This question paper comprises three sections A, B and C.
2. Section A has 16 questions: Q. No. 1 to 7 are MCQs carrying 1 mark each. Q. No. 8 and 9 are Assertion-Reason type questions carrying 1 mark each. Q. No. 10 to 12 are Short Answer I type questions carrying 2 marks each. Q. No. 13 to 15 are Short Answer II type questions carrying 3 marks each. Q. No. 16 is a Case-based question carrying 4 marks.
3. Section B has 13 questions: Q. No. 17 to 23 are MCQs carrying 1 mark each. Q. No. 24 is an Assertion-Reason type question carrying 1 mark. Q. No. 25 and 26 are Short Answer I type questions carrying 2 marks each. Q. No. 27 to 29 are Short Answer II type questions carrying 3 marks each. Q. No. 30 is a Case-based question carrying 4 marks.
4. Section C has 10 questions: Q. No. 31 and 32 are MCQs carrying 1 mark each. Q. No. 33 is an Assertion-Reason type question carrying 1 mark. Q. No. 34 and 35 are Short Answer I type questions carrying 2 marks each. Q. No. 36 to 38 are Short Answer II type questions carrying 3 marks each. Q. No. 39 is a Case-based question carrying 4 marks. Q. No. 40 to 42 are Long Answer type questions carrying 5 marks each.
5. All questions are compulsory. However, internal choice is provided in two questions of 2 marks, two questions of 3 marks and one Case-based question (last sub-part only) each in Sections A, B and C.
6. Draw neat diagrams wherever required.
7. Assume suitable values wherever required and state them clearly.
8. Do not use colours in the diagrams unless specifically asked to do so.
ABIOLOGY (30 Marks)
MCQs (1 mark each):
1
Which of the following is a characteristic of asexual reproduction?(a) Fusion of gametes(b) Large genetic variation(c) Production of genetically identical offspring(d) Slower rate of reproduction
2
The opening and closing of the stomatal pore is regulated by:(a) Guard cells(b) Epidermal cells(c) Leaf cells(d) Mesophyll cells
3
Which part of the human female reproductive system is responsible for carrying the baby after fertilization and implantation?(a) Oviduct(b) Ovary(c) Uterus(d) Vagina
4
What is the role of decomposers in an ecosystem?(a) Produce food from sunlight(b) Consume producers(c) Break down dead organic matter(d) Transfer energy to producers
5
Which of the following is a plant hormone that inhibits growth?(a) Auxin(b) Gibberellin(c) Cytokinin(d) Abscisic acid
6
Which of the following gases is produced during aerobic respiration?(a) Carbon dioxide and water(b) Carbon dioxide and energy(c) Oxygen and water(d) Carbon dioxide, water and energy
7
Which of the following is an example of a food chain with three trophic levels?(a) Grass → Goat → Lion(b) Grass → Deer → Tiger(c) Phytoplankton → Zooplankton → Fish(d) All of the above
Assertion-Reason Type Questions (1 mark each):
8
Assertion (A): The human eye has a power of accommodation.Reason (R): The ciliary muscles can change the focal length of the eye lens.(a) Both 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.
9
Assertion (A): Heredity ensures the continuity of species.Reason (R): Reproduction is a process that creates new individuals from existing ones.(a) Both 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.
Short Answer I (2 marks each):
10
What is the function of villi in the small intestine? How do they help in digestion?
11
Explain the difference between male and female gametes. Where are they produced in human beings?
12
Why are organisms like bacteria and fungi called decomposers? What would happen if they were absent in the ecosystem?
Short Answer II (3 marks each):
13
Explain the process of double displacement reaction with a suitable example. Differentiate it from a displacement reaction.
14
Describe the steps involved in the purification of a metal by electrolytic refining. OR Explain the difference between saturated and unsaturated hydrocarbons with respect to their bonding and reactivity.
15
How does the brain protect itself? Explain the role of the spinal cord in reflex actions. OR Explain the process of sexual reproduction in flowering plants, mentioning the roles of stamen and pistil.
Case-based Question (4 marks):
16
A farmer notices that his crops are being affected by pests. He decides to use a pesticide to get rid of them. The pesticide is sprayed on the crops.(a) What is the likely impact of this pesticide on the soil and water bodies?(b) Explain the phenomenon of biological magnification in relation to this pesticide.(c) Suggest an alternative method that the farmer could use to protect his crops without using harmful chemical pesticides.
Long Answer (5 marks each):
17
(a) Explain the process of urine formation in the human kidney. 3marks(b) What is meant by double circulation in human beings? Why is it necessary? (2 marks)
18
(a) Explain the working of the human brain in coordinating voluntary and involuntary actions. 3marks(b) How do plants respond to stimuli? Explain phototropism with a suitable example. (2 marks)
19
(a) Explain Mendel's experiments on pea plants, which led to the formulation of the Law of Segregation. 3marks(b) How is the sex of a child determined in humans? (2 marks)
BCHEMISTRY (25 Marks)
MCQs (1 mark each):
20
Which of the following is the most reactive metal among the given options?(a) Copper(b) Iron(c) Sodium(d) Aluminium
21
Which type of bond is formed in carbon compounds like methane?(a) Ionic bond(b) Covalent bond(c) Metallic bond(d) Hydrogen bond
22
When dilute sulphuric acid is added to iron(II) sulphate, what is observed?(a) A gas is evolved which turns lime water milky.(b) The colourless solution turns green.(c) A white precipitate is formed.(d) The blue colour of the solution turns green.
23
Which of the following indicators will show red colour in acidic solution and blue colour in alkaline solution?(a) Phenolphthalein(b) Methyl orange(c) Litmus(d) Turmeric
Assertion-Reason Type Questions (1 mark each):
24
Assertion (A): Alloys are used to lower the melting point of pure metals.Reason (R): Alloys are homogeneous mixtures of metals with other elements.(a) Both 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.
Short Answer I (2 marks each):
25
Write balanced chemical equations for the following reactions:(a) Calcium hydroxide reacts with carbon dioxide.(b) Zinc reacts with dilute hydrochloric acid.
26
What is meant by the term 'corrosion'? Give two methods to prevent the rusting of iron.
Short Answer II (3 marks each):
27
Explain the process of extraction of aluminium by electrolysis. OR Explain why ionic compounds conduct electricity in molten or aqueous state but not in solid state.
28
Describe the properties of ethanoic acid. How does it react with: (i) Sodium hydroxide? (ii) Sodium bicarbonate?
29
What is hydrogenation? Name the catalyst used and give one advantage of hydrogenation of oils. OR Explain the process of saponification. What are soaps?
Case-based Question (4 marks):
30
A student is performing an experiment to study the properties of acids. He takes two test tubes, A and B. In test tube A, he adds dilute hydrochloric acid and granulated zinc. In test tube B, he adds dilute acetic acid and granulated zinc. He observes that in test tube A, a gas is evolved rapidly, while in test tube B, the evolution of gas is slow.(a) Name the gas evolved in both the test tubes.(b) Write the balanced chemical equation for the reaction taking place in test tube A.(c) Explain why the rate of reaction is different in test tubes A and B.(d) What would happen if sodium hydroxide solution were added to hydrochloric acid? Write the reaction.
Long Answer (5 marks each):
31
(a) What are the methods to extract metals of: (i) low reactivity, and (ii) medium reactivity from their respective ores? 3marks(b) Explain the process of refining of copper by electrolytic refining. (2 marks)
32
(a) Explain the concept of homologous series. List any three characteristics of a homologous series. 3marks(b) Write the name and formula of the second member of the homologous series of alkanes. (2 marks)
33
(a) What are acids and bases? Explain the difference between strong and weak acids/bases. 3marks(b) What happens when an acid reacts with a metal oxide? Give an example. (2 marks)
CPHYSICS (25 Marks)
MCQs (1 mark each):
34
The SI unit of electric power is:(a) Volt(b) Ampere(c) Watt(d) Ohm
35
The phenomenon of scattering of light by particles in the atmosphere is responsible for:(a) Formation of rainbow(b) Blue colour of the sky(c) Twinkling of stars(d) Apparent flattening of the sun at sunrise and sunset
Assertion-Reason Type Questions (1 mark each):
36
Assertion (A): A magnetic field exerts a force on a current-carrying conductor.Reason (R): Moving magnets can induce current in a conductor.(a) Both 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.
Short Answer I (2 marks each):
37
State the relationship between the current flowing through a conductor and the potential difference across its ends. How is this relationship represented graphically?
38
What is meant by the term 'focal length' of a concave mirror? State the sign convention used for measuring distances in spherical mirrors.
Short Answer II (3 marks each):
39
Explain the formation of a rainbow with the help of a ray diagram. OR With the help of a ray diagram, explain the phenomenon of dispersion of white light by a glass prism.
40
(a) Define the term 'refractive index' of a medium. 1mark(b) Light enters from air to water. In which medium does it travel faster? Justify your answer. (2 marks)
41
Describe Fleming's left-hand rule and state its importance in the context of magnetic effects of electric current. OR Explain the working of an electric motor.
Case-based Question (4 marks):
42
A student is observing the reflection of a candle flame in a spherical mirror.(a) If the mirror forms a virtual and erect image, what type of mirror is it?(b) If the image formed is real and inverted, state two possible positions of the object.(c) If the image formed is always virtual, erect and diminished, what type of mirror is it?(d) If the image formed is virtual, erect and same size as the object, what type of mirror is it?
Long Answer (5 marks each):
43
(a) Draw a neat ray diagram to show the formation of an image by a convex lens when the object is placed between the optical centre and the principal focus. 2marks(b) State the lens formula and define the terms used in it. (1 mark)(c) Calculate the power of a convex lens which has a focal length of 20 cm. (2 marks)
44
(a) Explain the magnetic field produced by a current-carrying solenoid. 3marks(b) What is an electromagnet? How is it different from a permanent magnet? (2 marks)
45
(a) State the laws of refraction. 2marks(b) Calculate the focal length of a lens of power –2.0 D. What type of lens is it? (2 marks)(c) What is meant by the heating effect of electric current? (1 mark)
Answer Key
ABIOLOGY
1
(c) Production of genetically identical offspring
2
(a) Guard cells
3
(c) Stigma
4
(c) Break down dead organic matter
5
(d) Abscisic acid
6
(d) Carbon dioxide, water and energy
7
(d) All of the above
8
(a) Both A and R are true and R is the correct explanation of A.
9
(a) Both A and R are true and R is the correct explanation of A.
10
Villi are finger-like projections in the small intestine that increase the surface area for absorption of digested food. They contain blood capillaries and lymph vessels to absorb nutrients.
11
Male gamete: Sperm, produced in testes. Female gamete: Ovum, produced in ovaries.
12
Decomposers (bacteria and fungi) break down dead organic matter into simpler inorganic substances, returning nutrients to the ecosystem. Without them, dead organisms would accumulate, and nutrient recycling would stop.
13
Double displacement reaction: A reaction where ions of two compounds exchange places to form new compounds. Example: BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq). Displacement reaction: A reaction where a more reactive element displaces a less reactive element from its compound. Example: Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s).
14
Electrolytic refining: Impure metal is made anode, pure metal strip is cathode, and a solution of the metal salt is electrolyte. When current passes, impure metal dissolves from anode and pure metal deposits on cathode. OR Saturated hydrocarbons have only single bonds between carbon atoms and are less reactive. Unsaturated hydrocarbons have double or triple bonds between carbon atoms and are more reactive, undergoing addition reactions.
15
Brain protection: The brain is protected by the skull and cerebrospinal fluid. Spinal cord: It acts as a reflex center for simple reflexes, transmitting sensory information to the brain and motor commands from the brain. OR Sexual reproduction in flowering plants: Involves transfer of pollen from stamen to stigma (pollination), fertilization of ovule by pollen, and development of seed and fruit. Stamen produces pollen, pistil contains stigma, style, and ovary with ovules.
16
(a) Pesticides can contaminate soil and water bodies, harming aquatic life and potentially entering the food chain. (b) Biological magnification is the increasing concentration of pesticides in organisms at successively higher trophic levels. (c) Organic farming, integrated pest management, use of bio-pesticides, crop rotation.
BCHEMISTRY
20
(c) Sodium
21
(b) Covalent bond
22
(d) The blue colour of the solution turns green.
23
(c) Litmus
24
(a) Both A and R are true and R is the correct explanation of A.
25
(a) Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l) (b) Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)
26
Corrosion is the process where a metal is attacked by substances in the atmosphere, leading to its degradation. Methods to prevent rusting: Painting, galvanizing, oiling, greasing, alloying.
27
Aluminium extraction: Aluminium oxide (Al₂O₃) is dissolved in cryolite (Na₃AlF₆) and electrolysed. Molten Al is deposited at the cathode. OR Ionic compounds conduct electricity in molten/aqueous state because ions are free to move and carry charge. In solid state, ions are fixed in a lattice structure.
28
Ethanoic acid (acetic acid) is a weak acid. Reaction with NaOH: CH₃COOH + NaOH → CH₃COONa + H₂O. Reaction with NaHCO₃: CH₃COOH + NaHCO₃ → CH₃COONa + H₂O + CO₂.
29
Hydrogenation: Addition of hydrogen to unsaturated compounds (oils) in the presence of a catalyst (like Nickel or Palladium) to form saturated compounds (fats). Advantage: Converts liquid oils into solid/semi-solid fats, useful for making margarine and vanaspati ghee. Saponification: Reaction of an ester with sodium hydroxide to produce an alcohol and a sodium salt of carboxylic acid (soap). Soaps are sodium or potassium salts of long chain carboxylic acids.
30
(a) Hydrogen gas. (b) Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g). (c) Hydrochloric acid is a strong acid and dissociates completely, releasing more H⁺ ions, leading to a faster reaction rate than acetic acid, which is a weak acid and dissociates partially. (d) Neutralisation reaction: HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l).
CPHYSICS
34
(c) Watt
35
(b) Blue colour of the sky
36
(b) Both A and R are true but R is not the correct explanation of A.
37
Ohm's Law states that the potential difference across the ends of a conductor is directly proportional to the current flowing through it, provided the temperature remains constant. Graphically, V vs I is a straight line passing through the origin.
38
Focal length of a concave mirror: The distance from the pole to the principal focus. Sign convention: Distances are measured from the pole; distances in the direction of incident light are positive; distances opposite to the direction of incident light are negative; distances above the principal axis are positive; distances below are negative.
39
Rainbow formation: A rainbow is a natural spectrum of sunlight dispersed by water droplets in the atmosphere after rain. Light enters a water droplet, refracts, undergoes internal reflection, and refracts again as it emerges. Dispersion of white light by a prism: When white light passes through a prism, it splits into its constituent colours (VIBGYOR) because each colour bends at a different angle due to different refractive indices of the prism for different colours.
40
(a) Refractive index of a medium is the ratio of the speed of light in vacuum to the speed of light in that medium. (b) Light travels faster in air than in water because air is optically rarer than water, meaning it has a lower refractive index.
41
Fleming's left-hand rule: If the thumb, forefinger and middle finger of the left hand are stretched mutually perpendicular to each other, such that the forefinger points in the direction of the magnetic field, and the middle finger points in the direction of the current, then the thumb points in the direction of the force acting on the conductor. Importance: It helps determine the direction of the force on a current-carrying conductor in a magnetic field. Electric motor: Works on the principle that a current-carrying coil placed in a magnetic field experiences a torque and rotates. It converts electrical energy into mechanical energy.
42
(a) Convex mirror. (b) Object at infinity or beyond 2F. (c) Convex mirror. (d) Plane mirror.
43
(a) Ray diagram for object between O and F showing virtual, erect, enlarged image formed behind the lens. (b) Lens formula: 1/v - 1/u = 1/f. Where v = image distance, u = object distance, f = focal length. (c) P = 1/f (in metres). f = 20 cm = 0.2 m. P = 1/0.2 = +5.0 D.
44
(a) Magnetic field inside a solenoid: Uniform and strong, directed parallel to the axis of the solenoid. Field lines are close and parallel. (b) Electromagnet: A temporary magnet made by wrapping a coil around a soft iron core and passing current. Permanent magnet: Retains its magnetism even after the magnetizing field is removed.
45
(a) Laws of refraction: (i) The incident ray, the refracted ray and the normal to the interface of two media at the point of incidence all lie in the same plane. (ii) The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for a given pair of media. (b) P = -2.0 D. f = 1/P = 1/(-2.0) = -0.5 m. It is a concave lens. (c) Heating effect of electric current: The production of heat in a conductor when electric current flows through it due to the resistance of the conductor.
