SHARJAH INDIAN SCHOOL – BR.
JUWAIZA
MODEL EXAMINATION – JANUARY 2023-24 (SET A)
Grade: X Time Allowed: 3 hours
Subject: Science (086) Max. Marks: 80
Day & Date: Tuesday, 02/01/2024 Signature of the Invigilator: ___
Name of student: Section: Roll No.
General Instructions:
i. This question paper consists of 39 questions in 5 sections.
ii. All questions are compulsory. However, an internal choice is provided in
somequestions. A student is expected to attempt only one of these questions.
iii. Section A consists of 20 objective type questions carrying 1 mark each.
iv. Section B consists of 6 Very Short questions carrying 02 marks each. Answers to
thesequestions should in the range of 30 to 50 words.
v. Section C consists of 7 Short Answer type questions carrying 03 marks each.
Answersto these questions should in the range of 50 to 80 words
vi. Section D consists of 3 Long Answer type questions carrying 05 marks each.
Answer tothese questions should be in the range of 80 to 120 words.
vii. Section E consists of 3 source-based/case-based units of assessment of 04 marks
eachwith sub-parts.
SECTION - A
Select and write one most appropriate option out of the four options given for each of the
questions 1 – 20
Q.No Questions Marks
1 The reaction between MnO2 with HCl is depicted in the following diagram. It was 1
observed that a gas with bleaching abilities was released . The chemical reaction
between MnO2 and HCl is an example of:
a) displacement reaction b) combination reaction
c) redox reaction d) decomposition reaction.
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2 Which of the following is the correct observation of the reaction shown in the 1
above set up?
(a) Brown powder of Magnesium oxide is formed.
(b) Magnesium ribbon burns with brilliant white light.
(c) Colourless gas which turns lime water milky is evolved.
(d) Reddish brown gas with a smell of burning Sulphur has evolved.
3 Listed here is the reactivity of certain metals. 1
Which of the above metals are likely to be obtained in their pure states from the
Earth's crust?
(a) gold only B. (b) sodium only
(b) gold and platinum (d) zinc and sodium
4 Which of the following reactions is a neutralisation reaction? 1
(a) 4 Na + O2 ---> 2 Na2O
(b) Fe + 2 HCl ---> FeCl2 + H2
(c) MgO + H2O ---> Mg(OH)2
(d) HNO3 + NaOH ---> NaNO3 + H2O
5 Which of the following salts does not contain water of crystallization? 1
(a) Blue vitriol (b) Baking soda
(c) Washing soda (d) Gypsum
6 The first member of the alkyne homologous series is 1
(a) propyne (b) ethyne
(c) methane (d) ethene
7 When aqueous solutions of potassium iodide and lead nitrate are mixed, an 1
insoluble substance separates out. The chemical equation for the reaction
involved is :
(a) KI + Pb(NO3)2 →PbI + KNO3
(b) 2KI + Pb(NO3)2 →PbI2 + 2KNO3
(c) KI + PbNO3 → PbI + KNO3
(d) KI + PbNO3 →PbI2 + KNO3
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8 The action of which among the following is crucial to the formation of ozone? 1
(a) Humans (b) sunlight (c) carbon dioxide (d) chlorofluorocarbons
9 In following diagram, the parts A, B and C are sequentially 1
(a) radicle, cotyledon and plumule (b) plumule, cotyledon and radicle
(c) plumule, radicle and cotyledon (d) cotyledon, plumule and radicle
10 In the given food chain, suppose the amount of energy at fourth trophic level is 5 1
KJ. What will be the energy available at the producer level?
Grass → Grasshopper → Frog → Snake Hawk
(a)5 KJ (b) 50 KJ (c) 500KJ (d) 5000KJ
11 Select the correct statement regarding p, q , r and s . 1
(a) Exchange of gases takes place in r and oxygenated blood is carried back
through aorta
(b) q represents pulmonary artery that carries oxygenated blood from lungs to
heart.
(c) Exchange of gases and substances takes place in s and deoxygenated blood
is then carried back to the lungs through vena cava.
(d) p represents pulmonary veins that carries deoxygenated blood from heart to
lungs.
12 Select the mismatched pairs : 1
(a) Adrenaline-pituitary gland
(b) Testosterone -testes
(c) Estrogen -ovary
(d) Thyroxine -thyroid gland
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13 A student obtained a sharp image of the grill of a window in the laboratory on a 1
screen, using a convex lens. For getting better results, her teacher suggested
focusing on a distant tree instead of the grill. In which direction should the lens
be moved for this purpose to get a sharp image on the screen?
(a) behind the screen (b) very far away from the screen
(c) towards the screen (d) away from the screen
14 The face of the moon that is visible to us is called as the near side and the face of 1
the moon which is invisible to us is called as far side. What colour would the sky
appear to an astronaut standing on the "far side" of the Moon and why?
(a) blue, as the Moon's atmosphere scatters sunlight just like Earth
(b) white, as the Moon's surface reflect all the light that falls on it
(c) black, as there is no atmosphere on Moon to scatter sunlight
(d) black, as sunlight does not fall on the far side of the Moon
15 When an ‘X’ bearing sperm fertilises the egg. The resulting zygote has the 1
following combination of chromosomes:
(a)44+ XX (b) 44+ XY (c) 22 + XX (d) 22 + XY
16 Which is the first enzyme to mix with food in the digestive tract? 1
(a)Pepsin (b) Cellulose (c) Amylase ( d) Trypsin
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): Sodium and Potassium are stored under kerosene 1
Reason(R): Sodium and Potassium belong to group I and are alkali metals.
18 Assertion(A): During the night the effect of root pressure in transport of water is more 1
important.
Reason(R): Stomata is open during day, transpiration takes place which help in
transport of water
19 Assertion (A): On freely suspending a current carrying solenoid, it comes to rest in 1
Geographical N-S direction.
Reason(R) : One end of current carrying straight solenoid behaves as a North pole and
the other end as a South pole, just like a bar magnet.
20 Assertion (A): The offspring produced by sexual reproduction is likely to adjust better 1
in environmental fluctuation.
Reason(R): During the fusion of gametes there is mixing of genetic material from two
parents.
SECTION – B
Q. no. 21 to 26 are very short answer questions.
21 2
Write the common name of CaOCl2. Write the equation involved in its preparation.
Give any one uses of it.
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22 (i)In the given diagram, name the parts where, 2
(a) pollen grains are produced and
(b) pollen grains are transferred.
(ii) What happens to ovule and ovary after fertilisation?
23 A plant X was enclosed in a glass jar with some lizards. A similar plant Y was 2
enclosed in another glass jar but without lizards. Both the jars are kept under same light
conditions for few hours. Which plant is likely to photosynthesize more and why?
OR
Proteinuria is a condition in which significant amount of protein can be detected in
urine. Which process in nephron is likely to be affected causing proteinuria? Justify.
24 Absolute refractive indices of two media P and Q are 1.33 (nP) and 2.52 (nQ) 2
respectively. The speed of light in medium P is 2 x 108 m/s. What would be the speed
of light in vacuum and in medium Q (VQ)?
25 Compare the power used in the 2 Ω resistor in each of the following circuits: 2
(i) a 6 V battery in series with 1 Ω and 2 Ω resistors, and
(ii) a 4 V battery in parallel with 12 Ω and 2 Ω resistors.
OR
The following diagram shows two parallel straight conductors carrying same current.
Copy the diagram and draw the pattern of the magnetic field lines around them
showing their directions. What is the magnitude of magnetic field at a point ‘X’ which
is equidistant from the conductors?
26 What is feedback mechanism of hormonic regulation? Take the example of insulin to 2
explain this phenomenon.
SECTION - C
Q.no. 27 to 33 are short answer questions.
27 A metal X is obtained from its chloride salt by exposure to sunlight. 3
(a) Identify metal X
(b) In which section of the reactivity series of metals- top, middle or bottom, is it likely
to be placed? Justify your answer.
(c) Identify the type of reaction the chloride salt of metal X undergoes on exposure to
sunlight. Write the balanced chemical equation.
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28. Salts are formed by the neutralisation reaction between an acid and a base. Complete 3
the following table by filling the missing data:
Nature of the
salt
Name of Parent Parent (Acidic/ basic/
Sl.NO: the salt Formula Base Acid neutral)
Copper
1 sulphate ------------- Cu(OH)2 ------------ --------------
2 ------------ Na2CO3 ----------- H2CO3 ---------------
OR
(i) Suggest one remedial measure each to counteract the change in pH in human
beings in following cases.
(a) Production of too much acid in stomach during indigestion
(b) Stung by honey bee / nettle leaves.
(ii) Fresh milk has a pH of 6. When it changes in to curd will its pH increase or
decrease? Why?
29 3
The pyramid representing the land ecosystem is traditional with producers being
greater in mass than primary consumers and so on. Sometimes, in aquatic ecosystems,
an inverted pyramid exists. Here, the total mass of producers (phytoplankton) is much
smaller than the top consumers (big fishes).
(a) Which level is likely to have the most amount of energy in such an aquatic
ecosystem? Give a reason to support your answer.
(b) Such aquatic ecosystems are not considered to be sustainable. Justify this
statement.
30 Name the plant Mendel used for his experiment. What type of progeny was obtained 3
by Mendel in F1 and F2 generations when he crossed the tall and short plants? Write the
ratio he obtained in F2 generation plants.
31 (a) Explain the term ‘absolute refractive index of a medium’ 3
(b)A glass slab made of a material of refractive index n1 is kept in a medium of
refractive index n2. A light ray is incident on the slab. Draw the path of the rays of light
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emerging from the glass slab, if (i) n1> n2 (ii) n1 = n2
32 (i)State the law that explains the heating effect of current with respect to the 3
measurable properties in an electrical circuit.
(ii) Why are the conductors of electric heating devices, such as bread-toasters
and electric irons, made of an alloy rather than a pure metal?
33 Although electric kettle and electric toaster were used simultaneously in the kitchen to 3
prepare breakfast for the family, yet the two devices could work efficiently due to
‘fuse’ used in the electric circuit.
(i) How is a fuse connected in an electric circuit?
(ii)What is the function of a fuse?
(iii) A device uses 1 kW electric power when operated at 220 V. Calculate the rating
of the fuse to be used.
SECTION - D
Q.no. 34 to 36 are long answer questions.
34 (i) An unsaturated hydrocarbon P has the chemical formula C2H4. 5
(a) Write the name and structural formulae of hydrocarbon P.
(b) Write the chemical reaction to convert ethanol (CH3 - CH2 - OH) to hydrocarbon P.
(c) Describe the type of flame that P produces on combustion.
(ii) Identify hetero atom(s) (functional group) in the following compounds :
(iii) A carbon compound Q has six carbon atoms and six hydrogen atoms.
(a) Identify Q.
(b) Is Q a saturated or unsaturated carbon compound? Justify your answer by drawing
the structural formula.
OR
An organic compound ‘X’ is a liquid at room temperature. It is also a very good solvent
and has the molecular formula C2H6O. Upon oxidation ‘X’ gives ‘Y’. ‘Y’ releases a gas
‘W’ with brisk effervescence on reacting with NaHCO3. X reacts with Y in the presence
of conc.H2SO4to give another compound ‘Z’ which has a pleasant smell. Z.
(a) Give the chemical name and chemical formula of Y.
(b) How will you test for the gas ‘W’?
(c) Depict the formation Y and Z using chemical equations.
(d) Name the reaction of formation of ‘Z’.
(e) Give any one use of ‘Z’?
35 i) Draw a diagram of human respiratory system and label on it the following parts: 5
(a) Larynx (b) Trachea (c) Bronchi (d) Alveolar sac
ii) What advantage over an aquatic organism does a terrestrial organism have with regard
to obtaining oxygen for respiration?
OR
a) Sagar saw a beautiful rose and smelled it. As he was smelling it, he happened to
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touch a thorn and pull his hand away. State TWO differences and similarities each in
the way the nervous system performs the two actions.
b) Are all involuntary actions reflex actions? Justify.
36 5
The above image shows a thin lens of focal length 5m.
(i) What is the kind of lens shown in the above figure?
(ii) If a real inverted image is to be formed by this lens at a distance of 7m from the
optical centre, then show with calculation where should the object be placed?
(iii) Draw a neatly labelled diagram of the image formation mentioned in (ii)
OR
A student has focussed the image of an object of height 3 cm on a white screen using a
concave mirror of focal length 12 cm. If the distance of the object from the mirror is 18
cm, find the values of the following :
(i) Distance of the image from the mirror
(ii) Height of the image
(iii) Draw a ray diagram to show the formation of the image in this case.
SECTION - E
Q.no. 37 to 39 are case - based/data -based questions with 2 to 3 short sub - parts.
Internalchoice is provided in one of these sub-parts.
37 The melting points and boiling points of some ionic compounds are given below 4
These compounds are termed ionic because they are formed by the transfer of electrons
from a metal to a non-metal. The electron transfer in such compounds is controlled by
the electronic configuration of the elements involved. Every element tends to attain a
completely filled valence shell of its nearest noble gas or a stable octet.
(i) Show the electron transfer in the formation of Calcium oxide.
(ii) Beryllium Be and Chlorine Cl, form an ionic bond. In order for the compound to be
neutral ,what must the formula look like?
(iii) (A)The electronic configuration of some elements is given in the table below.
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(a) Identify any two pairs of elements that will react to form compounds by a transfer
of electrons.
(b) Write the molecular formula of the compounds formed by the pairs of elements
identified in (a)
OR
(iii) (B) Give reasons :
(a) Why do ionic compounds in the solid state not conduct electricity?
(b) Why is sodium chloride soluble in water but not in kerosene?
38 The excretory system of human beings includes a pair of kidneys, a pair of ureters, a 4
urinary bladder and a urethra. Kidneys are located in the abdomen, one on either side
of the backbone. Urine produced in the kidneys passes through the ureters into the
urinary bladder where it is stored until it is released through the urethra.
a) Name the filtration units of kidneys. What is the need to have a transport
system in complex organisms?
b) What are the strategies of plants to get rid of their wastes?
OR
b) What will happen, if one kidney of a person is removed?
39 Rahima was investigating a circuit for her school project. She wanted to demonstrate 4
the effect of length on the resistance of a conductor. The following is the given circuit
with resistors A and B that are made of the same metal and the same thickness but ‘A’
is twice as long as ‘B’. The total current in the circuit is 6 A and the Voltage of the
battery is 12 V.
a) What will be the resistance in the circuit?
b) Determine the value of ‘RA’ and ‘RB’.
c) Determine the current in both the ammeters. Will the current in ‘A1 ‘and ‘A2’ be
the same? Justify your answer.
OR
c) Define resistivity. What are the factors affecting the resistivity of a conductor?
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