Wednesday, January 25, 2012

CBSE MODEL TEST PAPER – 2012 Class – X Subject – Science

CBSE MODEL TEST PAPER – 2012

Subject – Science
Class – X
Time allowed: 3 hrs.] [MM: 80
General Instructions:
1. The question paper comprises of two sections, A and B. You
are to attempt both the sections.
2. All questions are compulsory.
3. There is no overall choice. However internal choice has
been provided in all the three questions of five marks category.
Only one option in such question is to be attempted.
4. All questions of section A and all questions of section B are
to be attempted separately.
5. Question numbers 1 to 4 in section A are one mark questions.
These are to be answered in one word or one sentence.
6. Question numbers 5 to 13 are two mark questions, to be
answered in about 30 words each.
7. Question numbers 14 to 22 are three mark questions, to be
answered in about 50 words each.
8. Question numbers 22 to 25 are five mark questions, to be
answered in about 70 words each.
9. Question numbers 26 to 41 are multiple choice questions
based on practical skills. Each question is of one mark.
You are to select one most appropriate response out of the
four provided to you.
Section – A
Q.1 What would be the electron dot structure of a molecule of
sulphur which is made up of eight atoms of sulphur?
Q.2 When a red rose is seen in green light, explain the colour
it will appear to be.
Q.3 Which of the following belong to the same trophic level?
Grasshopper, frog, grass, lizard
Q.4 How does O3 layer of atmosphere protect the human on earth?
Q.5 Three elements A,B and C have 3,4 and 2 electrons
respectively in their outermost shell. Give the group number
to which they belong in the Modern Periodic Table.
Also give their valencies.
Q.6 Identify the elements with the following property and
arrange them in increasing order of their reactivity.
a. An element which is a soft and reactive metal.
b. The metal which is an important constituent of limestone
c. The metal which exists in liquid state at room temperature.
Q.7 What are different methods of contraception? Which technique
of contraception may be effective to prevent sexually
transmitted diseases?
Q.8 A) In the human body what is the role of:
i) Seminal vesicles and ii) Prostate gland.
B) List two functions performed by testes in human beings.
Q.9 An object 3.0cm high is placed at a distance of 24cm in
front of a convex lens of focal length 16cm. Find the position,
nature and size of the image formed. (v = + 48cm, hi
= - 6 cm, the image is real, inverted and larger in size)
Q.10 What is meant by ‘dispersion of white light? Draw a
ray diagram to show dispersion of white light by a glass
prism. Why do we get different colours of light.
Q.11 Write the function of the following parts of human eye:
a) Iris b) Ciliary muscles
c) Pupil d) Eye lens.
Q.12 Define fossil fuels. Give two examples. Write two steps to
conserve fossil fuels.
Q.13 Briefly mention their contribution (any two)
a. Local people in Sal forests management in West
Bengal in 1980s
b. Woman folk of village Reni Gharwal in Himalayas in 1970s.
c. Bishnoi community of Rajasthan in conservation .
Q.14 a) Why does carbon form largest number of compounds?
b) Why are some of these called saturated and other
unsaturated compounds?
c) Write the names of the compounds:
i) CH3CH2Br
ii) H H H H
I I I I
H C C C C C C H
I I I I
H H H H
Q.15 Table given shows a part of the periodic table:
H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
Using the table explain why
a. Li and Na are considered as active metals?
b. Fluorine is more reactive than chlorine?
c. Atomic size of Mg is less than that of Na?
Q.16 a) Draw the structure of a flower and label any four
parts of it.
b) Give one example to each. Vegetative propagation
done by: a) roots, b) stems, c) leaves
Q.17 Mendel studied the inheritance pattern of traits in
pea plants. According to this study he obtained 9:3:3:1
ratio for certain traits in progeny of F2 generation. Based
on it, answer the followinga.
Which traits did he study? Give the representation.
b. What was the trait of progeny of F1?
c. What rule does this inheritance pattern suggest?
Q18 a) What is genetic drift?
b) How do genetic drift, mutation and natural selection play
a dominant role in the process of evolution?
Q.19 a) What is variation?
b) Describe the role of variations in providing survival and
advantage to the organism of a species.
Q.20 a) Define refractive index of a medium.
b) Light enters from air to glass plate. If the speed of light
in vacuum is 3 ×108 m/s and the speed of light in glass is
2 × 108 m/s, what is the refractive index of glass?
Q.21 Draw a ray diagram in each of the following cases to
show the position and nature of the image formed when
the object is placed:
i) Between optical centre and principal focus (F) of a convex
lens.
ii) at 2F of a convex lens.
Q.22 a) Define far point of eye and write its value for a person
of normal vision.
b) The far point of a myopic person is 80cm in front of
the eye. What is the power of the lens required to correct
the problem?
Q.23 a) Classify the following as alkane, alkene and alkyne:
CH4, C2H4, C3H4, C4H10, C2H2
b) What is substitution reaction? Which of the above compounds
undergo substitution reaction?
c) What happens when methane burns in air? Write chemical
equation.
d) Write the structure of the alcohol used in bear, whisky,
wine etc.
Or
a) Explain the given reactions with example –
i) Oxidation reaction
ii) Combustion reaction
iii) Hydrogenation reaction
b) Why detergents are better cleansing agents than
soaps? Explain.
Q.24a) What is budding? Explain by a series of labeled
sketches the manner in which reproduction occurs in Hydra.
b) Brophyllum reproduces asexually by vegetative propagation.
State two advantages Bryophyllum gets because
of this type of reproduction.
c) Give major difference between self pollination and cross
pollination.
Or
a) What is normal period of menstrual cycle in human
females? Why does menstruation occur?
b) Draw a labeled diagram of human female reproductive system.
c) Define the terms i) Placenta ii) Parturition

Q.25 a) Find the focal length of a lens of power – 2.0 D. What
type of lens is this?
b) What is Snell’s law?
c) Differentiate between a real image and a virtual image.
Or
a) Define 1 dioptre of power of a lens.
b) Name the type of mirror used in solar furnace. Support
your answer with reason.
c) A convex lens forms a real and inverted image of needle
at a distance of 50cm from it. Where is the needle
placed in front of the convex lens if the image is equal
to the size of the object? Also find the power of the lens.
Section – B
Q.26 In the following two diagrams, which represents the correct
path of the light ray through a rectangular glass slab?
(I) (II)
a. I only b.II only c.Both I & II d.None of these
Q.27 According to the law of refraction, angle of incidence (i)
and angle of refraction (r) are related as –
a) i > r b) r > i
c) i = r d) (a) and (b) both
Q.28 A student obtained a blurred image of an object on a
screen using a concave mirror. In order to obtain a sharp
image on the screen he will have to shift the mirror.
a. towards the screen
b. away from screen
c. either towards or away from the screen depending upon
the position of the object.
d. to a position very far away from screen.
Q.29 Which of the following diagrams gives a correct picture:
(III) (IV)
a. I b. II c. III d. IV
Q.30 A child is standing in front of a magic mirror. She finds the
image of her head bigger, the middle portion of her body of
same size and that of the legs smaller. The following is the
order of combinations for the magic mirror from the top.
a) plane, convex and concave
b) convex , concave and plane
c) Concave, plane and convex
d) Convex, plane and concave
Q.31 A student added a piece of zinc metal to four different test
tubes containing different solutions viz. CuSO
ZnSO
change?
a) CuSO
4, AgNO3,4 and FeSO4. In which test tube he observed no4
b) AgNO
3
c) ZnSO
4
d) FeSO
4
Q.32 Ethanoic acid was added to sodium bicarbonate
solution and the gas evolved was tested with a burning
splinter. The following four observations were reported.
a. The gas burns with the pop sound and the flame gets
extinguished.
b. The gas does not burn but the splinter burns with a pop
sound.
c. The flame extinguishes and the gas does not burn.
d. The gas burns with a blue flame and the splinter burn
brightly.
The correct observation is reported in:
a. (i) only b. (ii) only c. (iii) only d. (iv) only
Q.33 Which of the following is alkene?
a) C
20H40 b. C20H42 c. C20H38 d. C20H41
Q.34 Which of the following statements about graphite and
diamond is true
a. They have same crystal lattice structure
b. They have same degree of hardness
c. They have same electrical conductivity
d. They can undergo same chemical reaction
Q.35 Pure acetic acid (100%) is called glacial acetic acid because:
a. It freezes to an ice like mass and floats on water like glaciers
b. It becomes ice and sinks in water
c. It is soluble in water
d. It is sour in taste
Q.36 Seedless plants like banana can be propagated by –
a. Vegetative reproduction
b. Fission
c. Sexual reproduction
d. All of these
Q.37 Which of the following can regenerate its lost body part.
a. Hydra
b. Spirogyra
c. Rhizopus
d. Planaria
Q.38 The process represented in the diagram below is the –
a. Formation of spores in Amoeba
b. Budding in yeast
c. Binary fission in Amoeba
d. Binary fission is paramecium s
Q.39 Ovary in human female reproductive system produces
a. Ovum
b. Hormone
c. Ovum and hormones
d. None of these
Q.40 Normal gestation period in humans is –
a. 3 months
b. 6 months
c. 9 months
d. 12 months
Q.41 Only one parent is needed fora.
Sexual reproduction
b. Pollination
c. Asexual reproduction
d. All of these

Information Source : Amar Ujala (26.1.12)
http://epaper.amarujala.com/pdf/2012/01/26/20120126a_014145.pdf

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