CBSE Sample Papers for Class 10 SA2 Science Solved 2016 Set 8
1.Write the number of horizontal rows in the modern periodic table. What are these rows called ?
2.Give the respective scientific terms used for studying :
(i)the mechanism by which variations are created and inherited, and
(ii)the development of new type of organisms from the existing ones.
3.Mention the role of decomposers in our ecosystem.
4.In the food chain:
Grass -> deer -> lion
Operating in a forest, what will happen if all the :
(a)lions are removed ? (b) deers are removed ?
5.Differentiate between the food habits of organisms belonging to first and second trophic levels.
6.The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object relative to the mirror ? Draw ray diagram to justify your answer.
7.What is meant by functional group in carbon compounds ? Write in tabular form the structural formula and the functional group present in the following compounds :
(i)Ethanol (ii) Ethanoic acid –
8.Write the molecular formula of the following compounds and draw their electron-dot structures:
(i) Ethane (ii) Ethene
9.The position of these elements A, B and C in the periodic table are shown below :
Give reasons to explain the following :
(a)Element ‘A’ is a metal. (b) Element ‘B’ has larger size than ‘C’.
(c) Element ‘C’ has a valency – 3.
10.Given below are some elements of the modern periodic table :
4Be, 9Fe, 14Si,19K, 2oCa.
(a)Select the element that has one electron in the outermost shell and write its electronic configu ration.
(b)Select two elements that belong to the same group. Give reason for your answer.
(c)Select two elements that belong to the same period. Which one of the two has bigger atomic size ?
11.In human beings, the statistical probability of getting either a male or a female child is 50%. Give reasons and explain with the help of a diagram.
12.”A trait may be inherited, but may not be expressed.” Justify this statement with the help of a suitable example.
13.A pea plant with blue colour flower denoted by BB is cross-bred with a pea plant with white flower denoted by ww.
(a)What is the expected colour of the flowers in their Fa progeny ?
(b)What will be the percentage of plants bearing white flower in F2 generation, when the flowers of Fj plants were selfed ?
(c)State the expected ratio of the genotype BB and BW in the F2
14.’Variations that confer an advantage to an individual organism only will survive in a population/Justify.
15.An object of height 6 cm is placed perpendicular to the principal axis of a concave lens of focal length 5 cm. Use lens formula to determine the position, size and nature of the image if the distance of the object from the lens is 10 cm.
16.In a beautiful valley, there was a village. Trains passes from the village, the whistle and the sound of train mixed with the sound of waterfall seemed to be very pleasant to everyone. Children of that village loved to play near the railway track. On one very light foggy day, a group children found that a fish plate was missing from the track. Knowing this, all of the villagers became tensed. Aditya, one of the children suddenly put his ear to the line and tried to know whether a train is coming or not and he knew that a train is coming. He asked his friends to inform the railway cabin crew and he himself put off his red shirt and started running towards the train, waving his red shirt. Timely, the driver and cabin man got the information and a major accident hadn’t taken place.
(a)Name the two physical phenomenon of science used by Aditya.
(b)Why did Aditya use a red shirt instead of the other colours ?
(c)What moral values were shown by Aditya ?
17.(a) ” Stars seem higher than they actually are”
(b) ” The sky appears dark to passengers flying at very high altitudes”Justify these statements with reason.
18.What is meant by advance sunrise and delayed sunset ? Draw a labelled diagram to explain these phenomena.
19.What is the difference between the chemical composition of soaps and detergents ? State in brief the action of soaps in removing an oily spot from a shirt. Why are soaps not considered suitable for washing where water is hard ?
20.(a) What are the different methods of asexual reproduction ?
(b) Explain budding and regeneration with diagrams.
21.(a) Write the functions of the following in human female reproductive system :Ovary, oviduct, uterus.
(b) How does the embryo get nourishment inside the mother’s body ? Explain in brief.
22.(a) A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length. 5
(b) We see advertisements for eye donation on television or in newspapers. Write the importance of such advertisements.
23.Define the term absolute refractive index. The absolute refractive index of diamond is 2.42. What is the meaning of this statement ? Refractive indices of media A, B, C and D are given below :
In which of these four media is the speed of light (i) minimum and (ii) maximum ?
Find the refractive index of medium C with respect to medium B.
24.(a) Explain water harvesting. How can this technique help in the conservation of water ?
(b) “Energy flow in a food chain is unidirectional.” Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.
25.Four students performed an experiment of acetic acid with sodium carbonate (I), the sodium hydroxide (II), sodium bicarbonate (III) and sodium chloride (IV) separately. Each one brought burning candle near the mouth of the test-tube. The candle would not be exitnguished near the mouth of the test- tubes :
26.Which of the following statements is not correct ?
(A)Acetic acid is a weak acid and it ionizes only partially.
(B)Acetic acid turns red litmus blue but it does not affect blue litmus.
(C)Acetic acid is highly soluble in water
(D)Acetic acid reacts with sodium hydrogen carbonate to form a colourless and odourless gas.
27.at will you observe when solid sodium bicarbonate is added to acetic acid ?
(A)Solution turns light green (B) Brown fumes evolved
(C) Brisk effervescence occurred (D) A pungent smelling gas is evolved.
28.If the incident ray is in glass and its corresponding refracted ray is in air, the angle of incidence will be:
(A)equal to angle of refraction (B) smaller than the angle of refraction
(C) greater than the angle of refraction (D) none of the above
29.To trace the path of ray of light through a triangular glass prism, a student observes that the emergent ray:
(A)has bent away from the base of the prism
(B)has bent towards the base of the prism
(C)moves parallel to the direction of incident ray
(D)is not obtained
30.The following are the few steps of the procedure for determining the focal length of a given convex lens by obtaining a sharp image of a distant object:
(A)Measure the image obtained between the lens and the screen
(B)Select a suitable distant object
(C)Adjust the position of the lens from a sharp image
(D)Hold the lens between the object and screen with its faces parallel to the screen.
31.The correct sequence of the steps for the experiment is :
(A) (iii), (iv), (i), (ii) (B) (ii), (iv), (iii), (i)
(C) (iii), (i), (iv), (ii) (D) (ii), (iii), (iv), (i)
31.During budding in yeast, the parent cell divides by the process :
(A)Cytoplasm and nucleus divides at the same time.
(B)The nucleus first divides and then cytoplasm.
(C)The cytoplasm first divides and then nucleus.
(D)The cytoplasm and nucleus do not divide.
32.On germination of seeds, plumule is a :
(A)Future root. (B)Store food.
(C) Future leaf. (D) Future shoot.
33.An example of homologous organ
(A) Our arm and dog’s foreleg. (B)Our teeth and an elephant’s tusks.
(C) Potato and runners of grass (D)All of these.
34.A Student is viewing under a microscope a permanent slide showing various stages of asexual reproduction by budding in yeast. Draw diagrams of what he sees (in proper sequence).
35.Differentiate a real image from a virtual image giving two points of difference.
36.Select the correct observation about dilute solution of acetic acid. Give reason for your answer.
(A)It smells like rotten egg and turns blue litmus red.
(B)It smells like vinegar and turns red litmus blue.
(C)It smells like rotten egg and turns red litmus blue.
(D)It smells like vinegar and turns blue litmus red.
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