Karnataka Board SSLC Class 10 Science question paper solutions of 2015 considered to be a fruitful resource for students. These question paper solutions of 2015 can be accessed freely from our BYJU’S website. Students should refer to the solutions once they solve the question paper so that they can cross-check their answers and work on their mistakes. By doing so, they can avoid repeating the same mistakes while attempting the final question paper.

The solutions cover all the questions and each answer is solved in a proper manner so that students can easily grasp it. Download the solutions in pdf format from our website and students should keep it handy so that they can refer to it whenever possible. Solving previous year question papers helps them clear their doubts related to difficult and tricky questions.

Four alternatives are given for each of the following questions / incomplete statements. Only one of them is correct or most appropriate. Choose the correct alternative and write the complete answer along with its letter in the space provided against each question.

1. Electronic configuration of silicon is

(A) 1s², 2s² 2p⁶, 3s² 3p²

(B) 1s², 2s²2p⁶, 3s² 3p³

(C) 1s², 2s² 2p⁶, 3s²

(D) 1s², 2s²2p⁶, 3s² 3p⁴

Answer: A – 1s², 2s² 2p⁶, 3s² 3p²

2. A cyclist bends towards the centre while going in a circular path to

(A) move the cycle slowly

(B) gain necessary centrifugal force

(C) gain necessary centripetal force

(D) increase the friction.

Answer: C — gain necessary centripetal force

3. Which of the following is not a form of solar energy?

(A) Fossil fuel energy

(B) Wind energy

(C) Hydro energy

(D) Nuclear energy.

Answer: D — Nuclear energy

4. The alloy that contains copper and zinc as its constituents, is

(A) brass

(B) bronze

(C) german silver

(D) gunmetal.

Answer: A — brass

5. The measure to reduce energy crisis is

(A) Wastage of water

(B) Using fluorescent tube lights

(C) Luxurious lifestyle

(D) Each individual uses his own vehicle.

Answer: B — Using fluorescent tube lights

6. The reaction that is considered to be the source of solar energy is

(A) radioactivity

(B) thermonuclear fusion reaction

(C) nuclear fission reaction

(D) chemical reaction.

Answer: B — thermonuclear fusion reaction

7. The reducing agent used in the extraction of silicon is

(A) Magnesium

(B) Silica

(C) Phosphorus

(D) Sulphur.

Answer: A — Magnesium

8. The apparent change in frequency of wave motion due to the relative motion between the source and the observer is known as

(A) Raman effect

(B) Doppler effect

(C) Electromagnetic effect

(D) Tyndall effect.

Answer: B — Doppler effect

9. An example for a pentavalent dopant is

(A) Boron

(B) Antimony

(C) Galium

(D) Indium.

Answer: B — Antimony

10. The alkane among the following is

(A) C₂H₂

(B) C₂H₄

(C) C₆ H₆

(D) C₂ H₆

Answer: D – C₂ H₆

Fill in the blanks:

11. The device that converts solar energy into electrical energy is …………. .

Answer: Solar cell / Photo cell

12. The lightly doped region of a transistor is ……………………….. .

Answer: Base

13. The device used by the traffic control authorities to detect vehicle crossing speed limit is …………………………….. .

Answer: Radar gun

14. Match the names of hydrocarbons given in Column-A with their molecular formulae given in Column-B. Write the correct answer in the space provided:

Answer: a) — (iv) C₆H₆

b) — (ii) C₃ H₄

c) — (v) C₄ H₈

d) — (i) C₄ H₁₀

Answer the following questions:

15. Write the balanced chemical equation for the following chemical reaction: Magnesium reacts with dilute hydrochloric acid.

Answer: Mg + 2HCl MgCl₂ + H₂

16. What is cracking?

Answer: Heating of alkanes at a very high temperature in the absence of oxygen to decompose them to produce hydrocarbons of shorter chain length is called cracking.

17. Define half-life period of a radioactive element.

Answer: The time taken by the radioactive element to get reduced to half its initial amount is the half life period of that element.

18. What is uniform circular motion?

Answer: Circular motion with constant speed is called uniform circular motion.

19. Write the uses of a diode.

Answer: The uses of a diode

• Converts AC to DC
• Used in voltage regulating systems.

20. Name the system used to represent the brightness of a star.

Answer: Magnitude

Answer the following questions:

21. What is induced radioactivity? Explain with an example.

Answer: The phenomenon by which radioactivity is induced in an element is called induced radioactivity. When aluminium is bombarded by alpha particles, it produces radiophosphorus.

₁₃AI⁷+ ₂He⁴ → ₁₅P³⁰ + ₀n¹

22. Draw the diagram of a D.C. dynamo & label the parts.

Answer:

23. What are propellants? How do they work in vacuum?

Answer: The special type of fuels which contain both fuel and oxidants and used for rockets are called propellants. Propellants contain oxidants, which provide oxygen to the fuel and help them in burning even in vacuum.

24. Write any four methods of conservation of water.

Answer: Four methods of conservation of water

• Collection and use of roof water
• Improved methods of farming / irrigation
• Development of crop breeds that consume less water
• Preventing pollution of water
• Conserving and recharging groundwater
• Conservation of soil.

25. Draw the diagram of Helium-Neon laser tube and label the parts.

Answer:

26. Write the differences between A.C. dynamo and D.C. dynamo.

Answer: The differences between A.C. dynamo and D.C. dynamo

27. Draw the diagram of a single stage rocket and label the parts.

Answer:

28. “Soaps are eco-friendly than detergents.” Justify this statement.

Answer: Soaps are eco-friendly than detergents

• Detergents are non-biodegradable but soaps are biodegradable.
• Detergents pollute water & soil ; but soaps do not pollute water and soil.

29. Laser is used in eye surgery and industries. State the property of laser related to these uses.

Answer: Property of laser related to these uses

Eye surgery → directionality of laser

Industries → high power density of laser.

Answer the following questions:

30. What is polymerisation? Name one example each of the two types of synthetic polymers.

Answer: The process in which two or more molecules of a simple compound unite together to form a new compound is called polymerisation.

Addition polymers: Ex: Polythene

Condensation polymers: Ex: Nylon

31. What is Raman effect? Write the differences between Raman effect and Rayleigh scattering.

Answer: Raman Effect: When a beam of monochromatic light is passed through the transparent material, scattered light obtained contains higher and lower frequencies along with incident frequency.

Differences between Raman effect and Rayleigh scattering

32. Draw the diagram of a nuclear reactor and label the following parts:

(a) Moderator

(b) Heat exchanger.

Answer:

33. (a) State Universal law of gravitation.

(b) The distance between the two bodies is increased by two times.

Explain with the help of mathematical formula of gravitational law, whether the gravitational force between two bodies increases or decreases and by how many times.

Answer a: Every particle in the universe attracts every other particle with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them.

Answer b: F = GM₁M₂/d²

d = 2d, F₂ = GM₁M₂/(2d)²

F₂ = GM₁M₂/4d²

F₁/F₂ = GM₁M₂/d² × 4d²/GM₁M₂

F₁/F₂ = 4/1

F₂ = F₁/4 ⇒ When the distance between the two bodies is increased by two times the gravitational force decreases by 4 times.

Answer the following questions:

34. (a) What are galaxies? Name three types of galaxies.

(b) Why do the sun spots appear dark in colour?

Answer a: A huge group of stars held together by gravitational force is called a galaxy. Three types of galaxies are

• Spiral
• Elliptical
• Irregular

35. Draw the diagram of an electrolytic cell used in the extraction of coppercand label the following parts:

(a) Cathode

(b) Anode

(c) Copper sulphate solution.

Answer:

36. (a) Write the formula to calculate the efficiency of a heat engine.

(b) Mention any three advantages of an internal combustion engine.

Answer a: Efficiency of an engine = Work done/Energy supplied × 100

Four alternatives are given for each of the following questions / incomplete statements. Only one of them is correct or most appropriate. Choose the correct alternative and write the complete answer along with its letter in the space provided against each question.

37. …………….. is commonly called personality hormone.

(A) Adrenaline

(B) Thyroxine

(C) Insulin

(D) Glucagon.

Answer: B — Thyroxine

38. Which of the following vertebrates do not have teeth?

(A) Amphibia

(B) Aves

(C) Mammals

(D) Reptiles.

Answer: B — Aves

39. The red pigment present in Polysiphonia is

(A) Phycoerythrin

(B) Phycocyanin

(C) Chlorophyll

(D) Xanthophyll.

Answer: A — Phycoerythrin

40. The number of chambers in the heart of fish are

(A) four

(B) three

(C) two

(D) one.

Answer: C — two

41. The processes involved in oxygen cycle are

(A) Nitrification, Respiration

(B) Nitrification, Denitrification

(C) Photosynthesis, Denitrification

(D) Respiration, Photosynthesis.

Answer: D — Respiration, Photosynthesis

42. Match the names of epithelial tissues given in Column-A with their structure and location given in Column-B. Write the correct answer in the space provided:

Answer: a) — (v) flat cells, oesophagus

b) — (i) elongated cells, larynx

c) — (ii) ciliated cells, small intestine

d) — (vi) cube shaped cells, salivary gland

Answer the following in a sentence each:

43. It is hard to detect the colour of objects during night in dim light. Give reason.

Answer: Rods are sensitive to dim light but cannot distinguish colours. (Or cones cannot distinguish colours in dim light)

44. What is food adulteration?

Answer: The process of lowering the nutritive value of food, either by removing a vital component or by adding substances of inferior quality, is called food adulteration.

45. Human pinna is flexible. Why?

Answer: Pinna is made of cartilage. Cartilage is elastic and flexible.

46. Fibres are used to make gunny bags. Why?

Answer: Fibres are flexible

Answer the following questions in two or three sentences each:

47. Write any two characteristic features of reptiles.

Answer: Two characteristic features of reptiles are:

• Exoskeleton of horny scales
• Skin is dry
• Internal fertilization
• Both the limbs are pentadactyl.

48. What are the observations to be noted while purchasing packed fruit juice?

Answer: Observations to be noted while purchasing packed fruit juice are

• Date of manufacture
• Date of expiry
• Weight
• Ingredients
• FPO, stamp.

49. Forests help to reduce global warming. Justify.

Answer: Forests help to reduce global warming

• Trees absorb carbon dioxide from the atmosphere for photosynthesis.
• Trees regulate water cycle.

50. Mention any two disadvantages of using genetically modified foods.

Answer: Two disadvantages of using genetically modified foods are

• Human health may be upset
• May upset the delicate balance existing in nature.

51. Write any two differences between reservoir pool and exchange pool.

Answer: Reservoir pool:

• Movement of chemical substances is slow
• Involves non-living components
• Involves atmosphere, hydrosphere and lithosphere.

Exchange pool:

• Movement of chemical substances is rapid
• Involves living components
• Involves biosphere.

52. A monocot leaf is more vulnerable to wear and tear than a dicot leaf. Why?

Answer: A monocot leaf is more vulnerable to wear and tear than a dicot leaf

• Monocot leaf has parallel venation and has less of collenchyma.
• Dicot leaf has reticulate venation and has more of collenchyma.

Answer the following questions:

53. Explain the functioning of human ear.

Answer: The functioning of human ear are:

• The sound waves directed by the pinna to the tympanum, through the auditory canal make the tympanum to vibrate.
• These vibrations are carried to the internal ear through the chain of bones in the middle ear.
• The vibrations are further carried to the organ of Corti through perilymph and endolymph.
• These wave impulses are picked up by receptors in the organ of Corti and are carried through auditory nerve to the cerebrum which interprets the sound.

54. Draw a diagram showing the structure of HIV and label any two parts.

Answer:

55. Draw a diagram showing the vertical section of human eyeball and label the following:

(a) Lens

(b) Optic nerve.

Answer: