Victory Vault: Class 10 Science Preboard Sample Paper 2

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General Instructions: Class 10 Science Preboard Sample Paper

Please read the following instructions very carefully and strictly follow them: Class 10 Science Preboard Sample Paper

(i) This question paper contains 39 questions. All questions are compulsory. Class 10 Science Preboard Sample Paper

(ii) The question paper is divided into five sections – Sections A, B, C, D, and E. Class 10 Science Preboard Sample Paper

(iii) Section A – questions number 1 to 16 are multiple-choice type questions. For Questions number 17 to 20, two statements are given – one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer from the codes (A), (B), (C), and (D) as given below. Each question carries 1 mark. Class 10 Science Preboard Sample Paper

(iv) Section B – questions number 21 to 26 are very short answer-type questions. Each question carries 2 marks. Each question carries 2 marks. The answer to these questions should be in the range of 30 to 50 words. Class 10 Science Preboard Sample Paper

(v) Section C – Questions No. 27 to 33 are Short Answer type questions. Each question carries 3 marks. The answer to these questions should be in the range of 50 to 80 words. Class 10 Science Preboard Sample Paper

(vi) Section D – Questions No. 34 to 36 are long-answer type questions. Each question carries 5 marks. The answer to these questions should be in the range of 80 to 120 words. Class 10 Science Preboard Sample Paper

(vii) Section E – Questions No. 37 to 39 are of 3 source-based/case-based units of assessment carrying 4 marks each with sub-parts. Class 10 Science Preboard Sample Paper

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Section A (1 Mark Each)

1. During the electrolysis of water, a student observed that 20 cm³ of hydrogen gas was liberated at the cathode. The volume of oxygen gas liberated at the anode would be:
   1. 10 cm³
   2. 20 cm³
   3. 40 cm³
   4. 5 cm³
2. A solution turns red litmus paper blue. Its pH is likely to be:
   1. 1
   2. 4
   3. 5
   4. 10
3. Which of the following metals is stored in kerosene oil to prevent it from reacting with air and moisture?
   1. Iron
   2. Gold
   3. Sodium
   4. Silver
4. The IUPAC name of the compound CH₃-CH₂-OH is:
   1. Methanol
   2. Ethanal
   3. Ethanol
   4. Ethanoic acid
5. The movement of a plant part in response to light is called:
   1. Geotropism
   2. Phototropism
   3. Chemotropism
   4. Hydrotropism
6. In human females, an ovum is released from the ovary every month. This process is called:
   a. Menstruation
   b. Fertilisation
   c. Ovulation
   d. Implantation
7. A student obtained a sharp image of a distant object on a screen. The object is now moved closer to the lens. To get a sharp image again, the screen should be:
   a. Moved closer to the lens
   b. Moved away from the lens
   c. Placed at the focus of the lens
   d. Kept at the same position
8. The refractive index of diamond is 2.42. What is the meaning of this statement?
   a. Light travels 2.42 times faster in diamond than in a vacuum.
   b. Light travels 2.42 times slower in diamond than in a vacuum.
   c. Diamond reflects 2.42 times lighter than air.
   d. Diamond absorbs 2.42 times lighter than water.
9. Two devices of rating 220 V, 100 W and 220 V, 500 W are connected in parallel to a 220 V supply. The total current drawn from the supply will be:
   a. More for the 100 W device
   b. More for the 500 W device
   c. Same for both devices
   d. Zero
10. The magnetic field lines inside a current-carrying long straight solenoid are:
    a. Circular
    b. Parabolic
    c. Parallel to the axis
    d. Concentric circles
11. Which of the following is a biodegradable waste?
    a. Plastic bag
    b. Glass bottle
    c. Aluminium can
    d. Paper napkin
12. The reaction between Lead Nitrate solution and Potassium Iodide solution is an example of:
    a. Combination reaction
    b. Decomposition reaction
    c. Displacement reaction
    d. Double displacement reaction
13. The ability of carbon to form long chains is known as:
    a. Catenation
    b. Isomerism
    c. Allotropy
    d. Hydrogenation
14. Which part of the brain is responsible for maintaining the posture and balance of the body?
    a. Cerebrum
    b. Cerebellum
    c. Medulla
    d. Hypothalamus
15. A green plant is kept in a brightly lit area. The gas that will be most abundant around the plant is:
    a. Carbon dioxide
    b. Oxygen
    c. Nitrogen
    d. Water vapour
16. A refrigerator emits gases that degrade ozone. The compound responsible is:
    a. CO₂
    b. CFCs
    c. NO₂
    d. CH₄

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🔹 Assertion & Reason (1 mark each)

(A) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A). Class 10 Science Preboard Paper
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A). Class 10 Science Preboard Paper
(C) Assertion (A) is true, but Reason (R) is false. Class 10 Science Preboard Paper
(D) Assertion (A) is false, but Reason (R) is true. Class 10 Science Preboard Paper

17. Assertion: Copper does not displace hydrogen from dilute hydrochloric acid.
    Reason: Copper is below hydrogen in the reactivity series.
    
18. Assertion: Ethanoic acid is also known as glacial acetic acid.
    Reason: Ethanoic acid has a very low melting point and often freezes during winter in cold climates.
    
19. Assertion: The image formed by a convex mirror is always virtual and erect.
    Reason: A convex mirror has a wider field of view than a plane mirror of the same size.
    
20. Assertion: All the energy in a food chain ultimately comes from the sun.
    Reason: Green plants convert light energy into chemical energy during photosynthesis.

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🔹 Section B – Very Short Answer (2 marks each)

21. A student added a few pieces of aluminium metal to two test tubes, A and ,B containing aqueous solutions of Iron Sulphate and Copper Sulphate. After some time, a colour change was observed in one of the test tubes. In which test tube was the colour change observed? Write the balanced chemical equation for the reaction that took place.
22. The diagram below shows the position of various endocrine glands in the human body. A patient exhibits symptoms of persistent thirst, frequent urination, and blurred vision.

a. Which gland (A, B, C, or D) is most likely malfunctioning to cause these symptoms?
b. Name the hormone whose improper functioning is responsible for this condition.

23. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image.
24. State Ohm’s law. How can it be verified experimentally?
25. What is a food chain? Give an example of a food chain operating in a grassland ecosystem.
26. Why is it advised to use iodised salt in our diet?

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🔹 Section C – Short Answer (3 marks each)

27. 
    a. Write the chemical name and formula of Plaster of Paris.
    b. How is it prepared? Write the chemical equation.
    c. Why do doctors use Plaster of Paris for supporting fractured bones?
28. A student experimented with a young plant. The setup after 5 days of observation is shown in the diagram below.

(a) What is the specific name for this type of plant movement?
(b) Identify the plant hormone responsible for this phenomenon and the region where it is synthesised.
(c) Explain how this hormone causes the stem to bend towards the light.

29. 
    a. Draw a neat diagram of a neuron.
    b. How does a nerve impulse travel in our body? Explain briefly.
30. 
    a. What is meant by scattering of light?
    b. The sun appears reddish at sunrise and sunset. Explain why.
31. A household uses the following electrical appliances:
    i. Refrigerator of 400 W for 10 hours each day.
    ii. Two electric fans of 60 W each for 12 hours each day.
    Calculate the total energy consumed in April (30 days) in kilowatt-hours (kWh).
32. 
    a. What are trophic levels? How many trophic levels can a food chain have?
    b. Explain the phenomenon of “biological magnification” with the help of an example.
33. List three advantages of using CNG (Compressed Natural Gas) over petrol or diesel as a fuel in vehicles.

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🔹 Section D – Long Answer (5 marks each)

34. a. What are ionic compounds?
    b. List any three general properties of ionic compounds.
    c. Explain the formation of the ionic compound Magnesium Chloride (MgCl₂) by the transfer of electrons. (Write the electron-dot structures of Mg and Cl atoms and ions)
    OR
    a. Explain the process of neutralisation with the help of an example and a balanced chemical equation.
    b. A student tested the pH of four samples A, B, C, and D and recorded the observations as follows:

Sample	pH	Effect on Litmus
A	1	Turns blue to red
B	7	No change
C	11	Turns red to blue
D	5	Turns blue to red

Which sample is: (i) Highly acidic? (ii) A strong base? (iii) Neutral? Arrange the samples in increasing order of their H⁺ ion concentration.

35. 
    a. What is sexual reproduction?
    b. List and describe the main steps involved in sexual reproduction in flowering plants.
    c. How is the process of pollination different from fertilisation?
    OR
    a. Draw a neat, labelled diagram of the human digestive system.
    b. Explain the role of the following in the digestion process:
    (i) Saliva (ii) HCl in gastric juice (iii) Bile juice
36. 
    a. With the help of a ray diagram, show the path of a ray of light when it passes through a rectangular glass slab. Label the following on the diagram:
    (i) Incident ray,
    (ii) Refracted ray,
    (iii) Emergent ray,
    (iv) Angle of incidence,
    (v) Angle of refraction,
    (vi) Angle of emergence.
    b. State the laws of refraction.
    c. Why does the emergent ray bend but remain parallel to the incident ray?
    OR
    a. What is meant by the magnetic field? How is the direction of a magnetic field at a point determined?
    b. Draw the pattern of magnetic field lines around a current-carrying straight conductor. State the rule used to find the direction of the magnetic field.
    c. How will the strength of the magnetic field change when the current flowing through the conductor is doubled?

🔹 Section E – Source/Case-Based Questions (4 marks each)

37. A student set up an experiment to study the reaction between metals and acids. He took four test tubes and added 5 mL of dilute HCl to each. He then placed small, equal amounts of four different metals – Zinc (Zn), Iron (Fe), Copper (Cu), and Aluminium (Al) – in the four test tubes respectively. He observed the reactions and recorded his observations.
a. In which test tube(s) would he observe the evolution of a gas? Write a balanced chemical equation for one such reaction.
b. Identify the metal which will not show any reaction. Give a reason.
c. How can the gas evolved be tested? Describe the test.

38. In a forest ecosystem, grass is eaten by deer, which in turn is eaten by a tiger. The total energy available to the grass is 100,000 Joules.
a. Construct a food chain representing the given relationship.
b. Calculate the amount of energy that will be available to the tiger. (Assume 10% energy transfer at each step). Show your calculations.
c. Explain why the number of trophic levels in a food chain is limited.

39. A person is unable to see objects clearly beyond 2 meters. He visits an optician for a check-up.
a. Identify the defect of vision he is suffering from.
b. Suggest the type of lens required to correct this defect.
c. With the help of a ray diagram, show how this lens corrects the defect.

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