SCIENCE
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Time Allowed: 3 Hours Maximum Marks: 80
SECTION - A
1. Which of the following is the correct observation of the reaction shown in the
following set up?
Tong
Magnesium
ribbon
Burner Watch glass
Magnesium
oxide
(a) Brown powder of Magnesium oxide is formed.
(b) Colourless gas which turns lime water milky is evolved.
(c) Magnesium ribbon burns with brilliant white light.
(d) Reddish brown gas with a smell of burning Sulphur has evolved. 1
2. The electronic configurations of three elements X, Y and Z are X : 2, 8; Y : 2,
8, 7 and Z : 2, 8, 2. Which of the following is correct?
(a) X is a metal
(b) Y is a metal
(c) Z is a non-metal
(d) Y is a non-metal and Z is a metal 1
3. If 10 mL of H2SO4 is mixed with 10 mL of Mg(OH)2 of the same concentration,
the resultant solution will give the following colour with universal indicator:
(a) Red (b) Yellow
(c) Green (d) Blue 1
4. A white flowered plant is denoted as pp and a purple flowered plant is
denoted as PP. If the two plants are cross bred with each other, then what
will be the likely flower colour of the plants of F1 generation?
(a) White
(b) Purple
(c) Both purple and white
(d) Light purple 1
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5. Four combustion reactions of carbon compounds are shown below.
CH4 + O2→ CO2 + H2O + heat
CH3CHO + O → CO2 + H2O + heat
CH3CH2CH2OH + O2→ CO2 + H2O + heat
C6H6 + O2→ CO2 + H2O + heat
What can be concluded from the four reactions?
(I) All carbon compounds release oxygen on
combustion.
(II) All carbon compounds release water on
reacting with oxygen.
(III) All carbon compounds produce carbon
dioxide on reacting with oxygen.
Options:
(a) Only (I) (b) (I) and (II)
(c) (II) and (III) (d) (I), (II) and (III) 1
6. A solution of a base with pH 12.1 is given. Which of the following can be
done to decrease its pH?
(I) Add distilled water to it
(II) Add a solution of a different base with pH 8.7
(III) Add few drops of an acid with an unknown pH
(a) Only (I)
(b) Only (III)
(c) Only (I) and (II)
(d Any of (I), (II) and (III) 1
7. The resistance of a resistor is reduced to half of its initial value. In doing so,
if other parameters of the circuit remain unchanged, the heating effects in
the resistor will become:
(a) two times (b) half
(c) one-fourth (d) four times 1
8. Most of the digestion and absorption of the food takes place in the:
(a) small intestine (b) liver
(c) stomach (d) large intestine 1
9. Semen which contain millions of sperms also contains secretions of seminal
vesicle and prostrate gland (accessory glands). It makes the transport of
sperms easier and provide nutrition to sperms.
Correct sequence of organs in the male reproductive system for transport of
sperms is:
(a) Testis → vas deferens → urethra
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(b) Testis → ureter → urethra
(c) Testis → urethra → ureter
(d) Testis → vas deferens → ureter 1
10. Why should an individual organism waste energy on a process like
reproduction which it does not need to stay alive?
(a)To release excess energy stored by it
(b)To have genetic improvement
(c) To extend its own kind
(d)To provide variation 1
11. The hormone which increases fertility in males is called:
(a)oestrogen (b) testosterone
(c) insulin (d)growth hormone 1
12. Which of the following oxide(s) is/are soluble in water to form alkalies?
(I) Na2O (II) SO2
(III) K2O (IV) NO2
Options:
(a) (I) and (III) (b) (I) only
(c) (II) and (IV) (d) (III) only 1
13. In which of the following diagrams has the protractor (D) been correctly
placed to measure the angle of incidence and the angle of emergence?
I II III IV
Options:
(a)I, III (b)I, IV
(c) II, III (d)II, IV 1
14. The bluish colour of water in deep sea is due to:
(a)the presence of algae and other plants found in water
(b)reflection of the sky in water
(c) scattering of light
(d)absorption of light by the sea 1
15. What percentage of sun's energy falling on the leaves of green plants is
utilised by the plants in the process of photosynthesis and stored as chemical
energy of food?
(a)99% (b)10%
(c) 1% (d)20% 1
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16. As human being occupy the top level in any food chain, the maximum
concentration of insecticides get accumulated in our bodies. This phenomenon
is known as:
(a)Pollution
(b)Eutrophication
(c) Biological magnification
(d)None of these 1
Q. no 17 to 20 are Assertion - Reasoning based questions.
These consist of two statements – Assertion (a) and Reason (R). Answer these
questions selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true and R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
17. Assertion (A): Most of the salts when brought into the flame, impart
characteristic colours to the flame.
Reason (R): Potassium salts impart violet colour and barium salts im-
part green colour to the flame. 1
18. Assertion (A): Pollen grains are produced by all flowers.
Reason (R): Stamen is the male reproductive part of a flower and pro-
duces pollen grains. 1
19. Assertion (A): Electric appliances with metallic body have three pin
connection, whereas an electric bulb has a two pin
connection.
Reason (R): Three pin connection reduces heating of connecting wires. 1
20. Assertion (A): Improvements in our lifestyle have resulted in lesser
amounts of waste material generation.
Reason (R): Changes in packaging have resulted in much of the waste
generated to be non-biodegradable. 1
SECTION - B
21. A student prepared solutions of (I) an acid and (II) a base in two separate
beakers. She forgot to label the solutions and litmus paper is not available
in the laboratory. Since, both the solutions are colourless, how will she
distinguish between the two? 2
22. (i) Name the longest cell present in the human body.
(ii) Enlist the alternative name for "Hormones". 2
23. If human urine is allowed to stand for sometime, it smells of ammonia,
why? 2
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24. The table below shows the refractive index of different materials.
Flint
Water Kerosene Diamond
glass
Refractive index
of
1.33 1.44 1.65 2.42
the
material
The formula for calculating the refractive index (nm) of a material is,
Speed of light in X
nm = Speed of light in the medium
(A) What does X stand for ?
(B) The picture shows the path of light as it travels from one medium to
another.
incident ray
Medium 1
Medium 2 refracted ray
Which one of the two medium is rarer? 2
25. How much work is done in moving a charge of 2C from a point of 118V to a
point of 128V?
OR
Reema reverses the direction of the battery in the circuit. She turns the
circuit ON.
battery
+
Draw an arrow on the magnetic needle to show the correct deflection. 2
26. Presbyopia is a defect in vision. What is the primary cause of presbyopia? 2
SECTION - C
27. (A) Write two observations when lead nitrate is heated in a test tube.
(B) Name the type of reaction.
(C) Write a balanced chemical equation to represent the above reaction. 3
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28. Two resistors with resistance 5 Ohm and 10 Ohm respectively are to be
connected to a battery of 6V so as to obtain minimum and maximum current
flowing.
(A)How will you connect the resistors in each case?
(B)Calculate the strength of total current in the circuit in the two cases.
OR
(A) A metal X present in rock salt is highly reactive and it is stored un-
der kerosene to prevent it from catching fire. It exists in nature as XCl.
Identify the metal ‘X’. How can this metal be extracted from its chloride?
(B) How is calcination different from roasting? 3
29. (A)You are given two solutions A and B and their pH is 6 and 8 respectively.
(i) Which of the two solutions have more hydrogen ion concentration?
(ii) Which is acidic and which is basic?
(B) What is dilution? 3
30. Give reason:
(A) Water enters continuously into the root xylem.
(B) Swaati while advising her little brother that eating unhealthy food will
cause trouble in his digestion, also explained about the role of bile. She
told him that although bile does not contain any enzyme but it is essen-
tial for the digestion. Support Swaati’s view by giving a proper explana-
tion. 3
31. (A) Can a convergent lens in one medium become divergent in another
medium?
(B) Two thin lenses of focal length +10 cm and –5 cm are kept in contact.
What is the focal length and power of combination?
(C) A concave mirror of focal length f produces an image n times the size of
an object. What would be the object distance for which image is real? 3
32. (A) Write the mathematical expression for Joule’s law of heating.
(B) Compute the heat generated while transferring 96000 coulomb of charge
in two hours through a potential difference of 40 V. 3
33. How much work is done in moving a charge of 2C from a point of 118V to a
point of 128V? 3
SECTION - D
34. What is observed after about 1 hour of adding the strips of copper and
aluminium separately to ferrous sulphate solution filled in two beakers?
Name the reaction if any change in colour is noticed. Also, write chemical
equation for the reactions.
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OR
How can it be proved that the water of crystallisation makes a difference in
the state and colour of the compounds? 5
35. Draw a diagram of longitudinal section of a bisexual flower and label the
following:
Ovary, anther, style, stigma, filament
Identify from these the female reproductive organs and state one function
of each.
OR
How does our body respond when adrenaline is secreted into the blood? 5
36. (A) List the parts of human eye that controls the amount of light entering
into it. Explain how?
(B) Write the function of retina in human eye.
(C) If due to some disease or injury, the cornea of an eye is clouded, the vi-
sion is impaired and the person may become blind. This type of blindness
may be cured by replacing the defective cornea with the cornea of the
donated eye. Suggest some measures for motivating people to donate their
eyes after death. 5
SECTION - E
This section has 3 case-based questions (37, 38 and 39). Each case is followed
by 3 sub-questions (a), (b) and (c). Parts (a) and (b) are compulsory. However,
an internal choice has been provided in Part (c).
37. A piece of magnesium ribbon is added to a flask containing dilute hydrochloric
acid. Hydrogen gas is formed which is collected in the measuring cylinder.
The amount of hydrogen formed with time is plotted on a graph.
The line on the graph indicates the rate of chemical reaction occuring in the
flask.
Measuring cylinder
Magnesium ribbon Hydrogen bubbles
plus dilute
Water
hydrochloric acid
Reaction between magnesium and dilute hydrochloric acid
Time (minutes)
Volume of
Hydrogen
(cm2)
Time (minutes)
(A) At what time is the reaction rate fastest in the flask; at the start or in
the end. 1
(B) Which of these could increase the rate of reaction in the flask ?
P-Adding more acid to the flask 2
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Q-Heating the acid in the flask
R-Using a higher concentration of acid
(C) The reaction is repeated with magnesium powder in place of magnesium
ribbon under the same conditions. Will the reaction rate increase or de-
crease ?
Explain your answer with reference to the volume of hydrogen formed in
teh flask at 2 minutes. 2
38. Mendel blended his knowledge of Science and Mathematics to keep the count
of the individuals exhibiting a particular trait in each generation. He observed
a number of contrasting visible characters controlled in pea plants in a field.
He conducted many experiments to arrive at the laws of inheritance.
(A) What do the F1 progeny of tall plants with round seeds and short plants
with wrinkled seeds look like? 1
(B) What are recessive traits? 1
(C) Mention the type of the new combinations of plants obtained in F2 prog-
eny along with their ratio. If F1 progeny was allowed to self pollinate. 2
39. Anshu described the magnetic field of a magnet by drawing the magnetic
field lines. When he placed a small north magnetic pole in the magnetic field
created by the magnet, and it experienced a force. When the north pole was
free, it moved under the influence of magnetic field.
N
N N
N
N
S N
The path traced by a north magnetic pole free to move under the influence
of a magnetic field is called magnetic field line.
(A) What do the magnetic field lines determine? 1
(B) Anshu further placed a strong bar magnet vertically above a horizontal
wooden board. What would be the position of the magnetic lines of force?
2
(C) Draw magnetic field lines of a bar magnet. 2
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