SCIENCE X TERM-II
MODEL TEST PAPER – 2 (Unsolved)
(Based on the latest CBSE Sample Question Paper released by the CBSE, New Delhi)
Maximum Marks : 80
Maximum Time : 3 hours
Instructions : Same as in CBSE Sample Question Paper for SA-2 (Term II)
SECTION A
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1. How many dot structural isomers can you draw for pentane?
2. Why are the danger signals installed at the top of tall buildings red in colour.
3. What will happen if deer is missing in the food chain given below?
Grass → Deer → Tiger
4. Name an ecofriendly fuel.
5. Why do you think, the noble gases are placed in a separate group?
[1]
[1]
[1]
[1]
[2]
6. Name two elements you would expect to show chemical reactions similar to
magnesium. What is the basis of your choice?
[2]
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7. How will an organism be benefited if it reproduces through spores?
[2]
8. How does the embryo get nourishment inside the mother’s body?
[2]
9. (i) Define principal focus of a concave mirror.
[2]
(ii) The figure shows a ray of light as it travels from medium A to medium B. What
is the refractive index of medium B relative to medium A?
45°
Medium B
30°
60°
Medium A
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45°
10. The far point of a myopic person is 80 cm in front of the eye. What is the nature and
the power of lens required to enable him to see very distant objects clearly?
[2]
11. Why does the sky appear dark, instead of blue to an astronaut?
[2]
12. What are fossil fuels. Give two examples.
[2]
13. What forces work against an equitable distribution of our resources?
[2]
14. (i) What is a ‘homologous series’ of substances?
[3]
(ii) In an organic compound, which parts largely determine its physical and chemical
properties?
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(iii) Name the following compound:
—
H
—
H
20.
21.
22.
23.
—
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17.
18.
19.
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16.
H
O H
How and why does the atomic size vary as you go :
[3]
(i) from left to right along a period?
(ii) down a group?
(i) When does ovulation occur during the menstrual cycle in a normal healthy
female?
[3]
(ii) Draw a labelled diagram to show the reproductive system of a human female.
How do Mendel’s experiments show that traits are inherited independently?
[3]
What factors could lead to the rise of a new species?
[3]
Define the following terms :
[3]
(i) Evolution
(ii) Sex chromosome
(iii) Menstrual cycle
A convex lens has a focal length of 30 cm. Calculate at what distance should the object
be placed from the lens so that it forms an image at 60 cm on the other side of the
lens. Find the magnification produced by the lens in this case.
[3]
Why does a light ray incident on a rectangular glass slab immersed in any medium
emerges parallel to itself? Explain using a diagram.
[3]
Draw a ray diagram showing the dispersion through a prism when a narrow beam of
white light is incident on one of its refracting surfaces. Also indicate the order of the
colours of the spectrum obtained.
[3]
(a) What is fermentation?
[5]
(b) What role is played by yeast in the conversion of canesugar (C12H22O11) to
ethanol?
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15.
—
—
—
H—C—C—C—H
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(c) How may the following be obtained from pure ethanol? Express with the help of
chemical equations. (i) Sodium ethoxide (ii) Ethyl ethanoate (iii) Ethanal.
[5]
H
—
—
—
—
G
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OR
(a) The structural formula of an ester is :
H O
H
—
—
—
H — C — C — O —C — C — H
H
H H
Write the structural formulae of the corresponding alcohol and the acid.
(b) (i) Mention the experimental conditions involved in obtaining ethene from
ethanol.
(ii) Write the chemical equation for the above reaction.
(c) Explain the mechanism of the cleaning action of soaps.
2
24. What are the different methods of contraception. Discuss in brief.
OR
(a) Illustrate the following with the help of suitable diagrams :
(i) Spore fermentation in Rhizopus.
(ii) Multiple fission in Plasmodium.
(b) Describe the process of fertilisation in plants.
[5]
[5]
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25. An object 1 cm high produces a real image 1.5 cm high, when placed at a distance of
15 cm from a concave mirror. Calculate : (i) the position of the image, (ii) focal length
of the concave mirror.
[5]
OR
(i) A pencil when dipped in water in a glass tumbler appears to be bent at the
interface of air and water. Will the pencil appear to be bent to the same extent,
if instead of water we use liquids like kerosene or turpentine. Support your
answer with reason.
[5]
(ii) How is the refractive index of a medium related to the speed of light? Obtain an
expression for refractive index of a medium with respect to another in terms of
speed of light in these two media?
SECTION B
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26. Solutions of ferrous sulphate, zinc sulphate, copper sulphate and aluminium sulphate
were separately taken in four test tubes and some iron nails were placed in each of the
solutions. After few minutes, it would be observed that the colour of :
[1]
(a) all the four solutions changed
(b) solutions of zinc sulphate, copper sulphate and aluminium sulphate changed and
that of ferrous sulphate did not change.
(c) solutions of zinc sulphate and aluminium sulphate only changed.
(d) copper sulphate solution only changed.
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27. A thin plate of zinc metal is placed in a beaker containing aqueous ferrous sulphate
solution. The zinc plate is taken out after 15 minutes. The colour of iron sulphate
changes to :
[1]
(a) deep yellow
(b) deep green
(c) light blue
(d) colourless
28. Four students observed the colour and odour of acetic acid and its reaction with
sodium hydrogen carbonate. They tabulated their observations as given below : [1]
Student
A
B
C
D
Colour of acetic
acid
Odour of acetic
acid
Action with sodium
hydrogen carbonate
blue
colourless
light green
light brown
fruity
smell of vinegar
odourless
rotten egg
gas evolves without bubbles
effervescence
gas evolves without bubbles
effervescence
3
The correct set of observation is that of student :
(a) A
(b) B
(c) C
(d) D
29. Ethanoic acid reacts with sodium bicarbonate to form :
[1]
(a) sodium ethanoate and water (b) sodium ethanoate and carbon dioxide
(c) carbon dioxide and water
(d) sodium ethanoate, water and carbon dioxide
30. Acetic acid :
[1]
(a) is neutral towards litmus
(b) turns blue litmus red
(c) turns red litmus blue
(d) none of these
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31. Parallel rays, from a distant tree, incident on the device X, form its distinct image on
a screen as shown. The diagram correctly showing the image of the tree on the screen,
is diagram :
[1]
X
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X
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A
(a) A and the device X is a convex lens
(b) A and the device X is a concave mirror.
(c) B and the device X is a convex lens
(d) B and the device X is a concave mirror.
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32. A pencil is held close to a spherical mirror. It is found that the image formed in the mirror
is virtual and enlarged. The spherical mirror is :
[1]
(a) convex in nature
(b) concave in nature
(c) partly convex and partly concave in nature
(d) none of these
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33. Parallel rays, from the top of a distant tree, incident on a concave mirror, form an
image on the screen.
[1]
A
B
C
4
D
The diagram correctly showing the image of the tree on the screen is :
(a) A
(b) B
(c) C
(d) D
34. A student traces the path of a ray of light passing through a rectangular glass slab. [1]
A
C
D
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B
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For measuring the angle of incidence, he must position the protector in the manner
shown in figure :
(a) A
(b) B
(c) C
(d) D
35. A student performs the experiment on tracing the path of a ray of light passing through
a rectangular glass slab for different angles of incidence. He measures the angle of
incidence ∠ i, angle of refraction ∠ r and angle of emergence ∠ e for all his
observations. He would find that in all cases :
[1]
(a) ∠ i is more than ∠ r but (nearly) equal to ∠ e
(b) ∠ i is less than ∠ r but (nearly) equal to ∠ e
(c) ∠ i is more than ∠ e but (nearly) equal to ∠ r
(d) ∠ i is less than ∠ e but (nearly) equal to ∠ r
36. The process represented in the diagram below is :
[1]
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(a) formation of spores in Amoeba
(b) formation of bud taking place in Amoeba
(c) identical gametes being formed in Amoeba
(d) formation of daughter cells in Amoeba
37. The budding in yeast is illustrated by the diagram :
(a) A
(b) B
(c) C
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[1]
(d) D
38. A chain of yeast cells is formed when :
(a)
(b)
(c)
(d)
yeast
yeast
yeast
yeast
cells
cells
cells
cells
[1]
do not separate after budding
are infected by a virus
stick to each other due to the presence of mucus
suffer from a disease
39. While performing the experiment with raisins to determine the percentage of water
absorbed by them, a student recorded the following data :
[1]
Weight of the water in the beaker = 50 g
Weight of raisins before soaking = 20 g
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Weight of raisins after soaking for one hour = 30 g
Weight of water left in the beaker after the experiment was over = 40 g
The percentage of water absorbed by raisins is :
(b) 20
(c) 45
(d) 50
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(a) 10
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40. A student put five raisins each in two beakers A and B. Beaker A contained 50 ml of
distilled water and beaker B had 50 ml of saturated sugar solution. After sometime, the
student would observe that :
[1]
(a) raisins in beaker A were more swollen than those in beaker B.
(b) raisins in beaker B were more swollen than those in beaker A.
(c) raisins in both beakers A and B were equally swollen.
(d) raisins in beaker A did not swell up at all.
41. A student soaked 10g raisins in 50 ml of distilled water in two beakers A and B each.
She maintained beaker A at 25°C and beaker B at 50°C. After an hour, the percentage
of water absorbed will be
[1]
(a) the same in both A and B
(b) more in A than in B
(c) more in B than in A
(d) exactly twice as much in B as in A
10. –1.25D
27. (d) 28. (b)
35. (a)
36. (d)
ANSWERS
20. – 60 cm, –1
29. (d)
30. (b)
37. (b)
38. (a)
6
25. – 22.5 cm, –9 cm
31. (a) 32. (b) 33. (b)
39. (d) 40. (a) 41. (c)
26. (d)
34. (b)