Select and write the most appropriate option out of the four options given for each of the questions 1-20. There is no negative mark for the incorrect response.
1. Select from the following a decomposition reaction in which source of energy for decomposition is light:
(3)2FeSO4→ Fe2O3 + SO2 + SO;
(b) 2H2O→ 2H2+O2
(c) 2AgBr 2Ag+ Br2
(d) CaCO3→ CaO + CO₂
2. Oxides of aluminium and zinc are
(a) acidic
(b) basic
(c) amphoteric
(d) neutral
3. Consider the following compounds:
FeSO4; CuSO4; CaSO4 Na2CO3
The compound having maximum number of water of crystallisation in its crystalline form in one molecule is:
(a) FeSO4
(b) CuSO4
(c) CaSO4
Na2CO3
4. The name and formula of third member of homologous series of alkyne is:
(a) Propyne C3H6
(b) Propyne C3H4
(c) Butyne C4H8
(d) Butyne C4H6
5. A metal and a non-metal that exists in liquid state at the room temperature are respectively:
1
(a) Bromine and Mercury
(b) Mercury and Iodine
(c) Mercury and Bromine
(d) Iodine and Mercury
6. MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
The reaction given above is a redox reaction because in this case:
(a) MnO2 is oxidised and HCl is reduced.
(b) HCl is oxidised.
(c) MnO, is reduced.
(d) MnO2 is reduced and HCl is oxidised.
8. Which one of the following statements is NOT true?
(a)/ DNA carries the information for inheritance of features from parents to the next generation.
(b) DNA is the information source for making proteins.
(c) Change in the information leads to different proteins.
Features will remain the same even if the protein changes.
9. In a nerve cell, the site where the electrical impulse is converted into a chemical signal is known as:
(a) Axon
(b) Dendrites
Neuromuscular junction
(d) Cell body
10. Chromosomes:
(1) carry hereditary information from parents to the next generation.
(ii) are thread like structures located inside the nucleus of an animal cell.
(iii) always exist in pairs in human reproductive cells.
(iv) are involved in the process of cell division.
The correct statements are:
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i), (ii) and (iv)
(d) (i) and (iv)
11. A stomata closes when:
(i) it needs carbon dioxide for photosynthesis.
(ii) it does not need carbon dioxide for photosynthesis.
(iii) water flows out of the guard cells.
(iv) water flows into the guard cells.
The correct reason(s) in this process is/are:
(a) (i) only
(b) (1) and (im)
(c) (ii) and (iii)
(d) (i) and (iv)
12. In which of the following organisms, multiple fission is a means of asexual reproduction?
(a) Yeast
(b) Leishmania
(c) Paramoecium
(d) Plasmodium
13. At what distance from a convex lens should an object be placed to get an image of the same size as that of the object on a screen?
1
(a) Beyond twice the focal length of the lens.
(b) At the principal focus of the lens.
(c) At twice the focal length of the lens.
(d) Between the optical centre of the lens and its principal focus.
14. The lens system of human eye forms an image on a light sensitive screen. which is called as:
(3) Cornea
(b) Ciliary muscles
(c) Optic nerves
(d) Retina
15. The pattern of the magnetic field produced inside a current carrying solenoid is:
16. Identify the food chain in which the organisms of the second trophic level are missing:
(a) Grass, goat, hon
(b) Zooplankton, Phytoplankton, small fish, large fish
Tiger, grass, snake, frog
(d) Grasshopper, grass, snake, frog, eagle
17. Assertion (A): The rate of breathing in aquatic organisms is much faster than in terrestrial organisms.
Reason (R): The amount of oxygen dissolved in water is very high as compared to the amount of oxygen in air.
Answer (c)
18. Assertion (A): The rainbow is a natural spectrum of sunlight in the sky.
Reason (R): Rainbow is formed in the sky when the sun is overhead and water droplets are also present in air.
Answer (c)
19. Assertion (A): Accumulation of harmful chemicals is maximum in the organisms at the highest trophic level of a food chain.
Reason (R): Harmful chemicals are sprayed on the crops to protect them from diseases and pests.
Answer (b)
20. Assertion (A) Hydrogen gas is not evolved when zinc reacts with nitric acid.
Reason (R): Nitric acid oxidises the hydrogen gas produced to water and itself gets reduced.
Answer (a)
SECTION-B
21. (i) Two magnetic field lines do not intersect each other. Why?
(t) How is a uniform magnetic field in a given region represented? Draw a diagram in support of your answer.
12. (A) Show how you would connect there tesistors each of resistance 6 D so that the combination han a resistance of 9. 11. Also justify your answer
OR
(By in the given circuit calculate the power consumed in watts in the
resistor of 2 Q
10
20
6V
23. A ray of light falls making an angle of incidence e on the surface of a glass slab. Draw a labelled ray diagram to show its path. Also mark lateral displacement on it.
24. (A) In which region of the brain is (i) modulla and (ii) cerebrum located? State one function of each.
OR
2
(B) Name a hormone that promotes the growth of tendrils and explain how they help a pea plant to climb up other plants.
2
25. Mention the pathway of urine in our body starting from the organ of its formation to its excretion. What will happen if the tubular part of the nephron does not work properly?
2
26. Translate the following statements into chemical equations and then balance them:
2
Solution of barium chloride and aluminium sulphate in water react to give insoluble barium sulphate and the solution of aluminium chloride.
(4) Aluminium metal reacts with steam to give aluminium oxide and hydrogen gas.
SECTION-C
27. 0) The pit of a sample of tomato juice is 4.6. How is this juice likely to be in taste ? Give reason to justify your answer
(1) How do we differentiate between a strong acid and a weak base in terms of ion-formation in aqueous solutions"
(iii) The acid rain can make the survival of aquatic animals difficult. How?
28. Write one chemical equation each for the chemical reaction in which the following have taken place:
Change in colour
3
(ii) Change in temperature
(m) Formation of precipitate
Mention colour change/temperature change (rise/fall/compound precipitated along with equation.
29. Define reflex action. With the help of a flow chart show the path of a reflex action such as sneezing.
30. In the context of the statement "chlorophyll is necessary for photosynthesis answer the following questions:
(1) What are variegated leaves? Give an example.
(ii) When leaf is boiled in alcohol, what happens to the colour of the leaf and the colour of the solution?
(iii) In what form is the carbohydrate produced, stored in the plant? Why is chlorophyll necessary for photosynthesis?
31 (A) Plants Deer Lion In the given food chain, what will be the impact of removing all the organisms of second trophic level on the first and third trophic level? Will the impact be the same for the organisms of the third trophic level in the above food chain if they were present in a food web? Justify.
OR
(B) A gas 'X' which is a deadly poison is found at the higher levels of atmosphere and performs an essential function Name the gas and write the function performed by this gas in the atmosphere. Which chemical is linked to the decrease in the level of this gas? What measures have been taken by an international
organization to check the depletion of the layer containing this gas
28. Write one chemical equation each for the chemical reaction in which the following have taken place:
3
410 Change in colour
(ii) Change in temperature
(ii) Formation of precipitate
Mention colour change temperature change (rise/fall)/compound precipitated along with equation
29. Define reflex action. With the help of a flow chart show the path of a reflex action such as sneezing
3
30. In the context of the statement "chlorophyll is necessary for photosynthesis" answer the following questions
(1) What are variegated leaves? Give an example.
(ii) When leaf is boiled in alcohol, what happens to the colour of the lest and the colour of the solution?
3
(mm) In what form is the carbohydrate produced, stored in the plant? Why is chlorophyll necessary for photosynthesis ?
31. (A) Plants Deer Lion
In the given food chain, what will be the impact of removing all the organisms of second trophic level on the first and third trophic level? Will the impact be the same for the organisms of the third trophic level in the above food chain if they were present in a food web? Justify
OR
(B) A gas 'X' which is a deadly poison is found at the higher levels of atmosphere and performs an essential function
Name the gas and write the function performed by this gas in the atmosphere. Which chemical is linked to the decrease in the level of this gas? What measures have been taken by an international organization to check the depletion of the layer containing this gas?