NATIONAL PUBLIC SCHOOL

YESHWANTHPUR, BANGALORE
HALF YEARLY EXAMINATION 2024-25
SUBJECT: SCIENCE
CODE:086

Class: 10 Max.Marks:80
Date: 02/09/2024 Time: 3 Hour
No. of pages: 08
General lnstructions:
i. This question paper consists of 39 questions in 5 sections.
i. Allquestions are compulsory. However, an internal choice is provided in some questions. Astudent is expected to
attempt only one of these questions.
ii.Section Aconsists of 20 objective type questions carrying 1 markeach.
iv. Section Bconsists of 6 Very Short questions carrying 02 marks each. Answers to these questions should be in the
range of 30 to 50 words.
v. Section Cconsists of 7 Short Answer type questions carrying 03 marks each. Answers to these questions should be in
the range of 50 to 80 words.
vi, Section Dconsists of 3 Long Answer type questions carrying 05 marks each. Answer to these questions should be in
the range of 80 to 120 words.
vii.Section Econsists of 3 source-based/case-based units of assessment of 04 marks each with sub parts.
Section-A
Select and write the most appropriate option out of the four options given for each of the questions 1 - 20.
1. The setting of the plaster of Paris takes place due to (1)
(a) oxidation (b) reduction (c) dehydration (d) hydration
2. Which of the following pairs will give displacement reactions? (1)
(a) NaCl solution and copper metal (b) MgCl2 solution and aluminium metal
(c) FeSO4 solution and silver metal (d) AgNO3 solution and copper metal
3. An aqueous solution turns the red litmus solution to blue. Excess addition of which of the following
given solutions would reverse the change? (1)
(a) Baking powder (b) Lime (c) Ammonium hydroxide (d) Hydrochloric acid
4. Which statements about the chemical reaction below are correct?
2PbO(solid) + C(s) > 2Pb(s) + COz(e) (1)
(i) Lead is getting reduced. (ii) Carbon dioxide CO, is getting oxidised.
(ii) Carbon is getting oxidised. (iv) Lead oxide is getting reduced.
(a) (ii) and (iv) (b) ()and (ii) (c) (),(ii) and (ii) (d) (iv)

5. Which of the following gases can be utilised for storing oily food for a long time? (1)
(a) Carbon dioxide or oxygen (b) Nitrogen or oxygen
(c) Carbon dioxide or helium (d) Helium or nitrogen

6. Which of the following oxides is amphoteric? (1)

(a) Na20 (b) Mgo (c) CaO (d) Alb0a

1
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()Agard cels, B-stomatal pore, Gnudles

11 Which one of thegiven statements isincorect?

(a) DNA has the complete information for a particular charecteristic
b) DNA is the molecule responsible for the irheritance of characteristic from parents to ofispring.
(d Change in information wil produce a ferent protein.
(d) Characteristics will remain the sane even if protein changes.

12 Which of the folowing statement(s) is (are) true about human heart? (1)
) Right atriunreceives oxygenated blood from lungs through pulmonary artery.
) Left atrium transfers oxygenated blood to left ventricde which sends it to various parts ofthe body.
() Right atrium receives deoxygenated bloodthrough vena cava from upper and lower body.
(v) Left atrium transfers oxygenated blood to aorta which sends itto diferent parts of the body
(a) (0) (b) ) and (iv) (c) () and (iü) (d) () and (iv)

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 (1)
13. The image shows the path of incident rays to a concave mirror.

Object

the image formation to take place? andF

Where would the reflected rays meet for (c) Between C
(d) Beyond C
(a) Behind the mirror (b) Between FandO
component in the circuit, will
show the
in 3 s. Which electrical
moving through it (1)
14. Acircuit has a charge of 2C
current?
current of 0.7 A
(b)Ammeter willshow a
(a) Voltmeter willshow a current of 6A (d) Resistor willshow a
current of 0.35 A
(c) Rheostat willshow a current of 0.7 A
Which of the following depicts tropic movements appropriately? (1)
15. Observe the three figures given below.

A B
(d) C only
(b) Aand C (c) Bonly
(a) B andc
(1)
orange have lost the capacity to produce
16. Plants like banana, rose, jasmine, (d) roots
(b) buds (c) flower
(a) seeds

Answer these questions

statements- Assertion (A) and Reason (R).
Question No. 17 to 20 consist of two
selecting the appropriate option given below:
correct explanation of A.
a) Both A and R are true, and R is the
Rare true, and Ris not the correçt explanation
of A.
b) Both Aand
c) A istrue but R is false.
d) Aisfalse but R is true.
cells of our body and provides energy.
()
17. Assertion (A): GIlucose combines with oxygen in the
the formation of products are called exothermic
Reason (R): Reaction in which heat is released along with
reactions.
electrochemical event. (1)
18. Assertion (A): A nerve impulse is an potential which spread down the nerve
Reason (R): In anerve impulse there are changes in the resting
fibre.
(1)
19. Assertion (A): Images formed on the retina are inverted
inverted image
Reason (R): The eye has a convex lens which forms real and
(1)
20. Assertion: All organisms reproduce for perpetuation of a population.
Reason: Reproduction is an al-inclusive characteristic of living organisms.
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 Section-B

Question No. 21 to 26 are very short answer questions

Z1. On heating blue coloured powder of copper (1) nitrate in a boiling tube, copper oxide (black), oxygen gas
& a brown gas "X" are formed. (2)
(a) Write a balanced chemical equation of this reaction.
(b) ldentify the brown gas (X) that is evolved.
(c) ldentify the type of reaction.

22. In the given diagram (2)

(a) Identify the parts labeled as Band .

A
B

(b) Reflex arcs have evolved in animals? Why?

23. Photosynthesis takes place in the leaves and the food prepared by it reaches other parts of the plants.
Name the process involved and explain. (2)
OR
Why is there a difference in the rate of breathing between aquatic organisms and terrestrial organisms?
Explain.

24. A nichrome wire has a resistance of 10 Q. Find the resistance of another nichrome wire, whose
length is three times and area of cross-section four times the first wire.
(2)

25. A student carries out an experiment and plots the V-l graph of three samples of nichrome wire
with resistances R1, R2, and R3 respectively as shown in the Figure.
(2)

.R/

Which of the above resistors give the maximum resistance? Why?

OR
a) Define the term 'volt'.
(6) Calculate the potential difference between the two terminals of a battery if 100 Jof work is
required to transfer 20 Cof charge from one terminal of the battery to the other.

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26. In one of the methods of propagation as shown in the figure below, Planaria A is cut horizontally
intothree pieces L, M andN and Planaria Bis cut vertically into two equal halves -0 and P. (2)

a complete organism? Why?

Which of the cut pieces of the two Planaria could regenerate to form
Section-C
Question No. 27 to 33 are short answer questions
(3)
27. Explain the following:
state, whereas it does conduct electricity in an
(a) NaCl is not a good conductor of electricity in the solid
aqueous solution as well as in molten state.
using electron dot structure.
(b) Explain the formation of ionic compound magnesium oxide by
identify the type of reaction ineach case. (3)
28. Write the balanced chemical equation for the following and
iodide (ag) + Barium bromide(s)
(a) Potassium bromide (ag) + Barium iodide (ag) ’ Potassium
(b) Hydrogen (g) + Chlorine (g) ’ Hydrogen chloride (e)
OR
Give reason:
(a) Copper powder becomes black on heating.
(b) We store silver chloride in dark-colored bottles.
a long time.
(c) Fat or oil containing foods become rancid whern left for (3)
29. Give reasons for the following:
(a) Alveoliin lungs are richly supplied with blood capillaries.
not carbon dioxide.
(b) Respiratory pigment in the blood takes up oxygen and
molecule is formed as an end product instead of CO2 in
(c) During anaerobic respiration, a 3-carbon
human beings.
(3)
30. Draw neat diagrams of the following: Bryophyllum
vegetative propagation in
(a) spore formation in Rhizopus (b) binary fission in amoeba (c)
31. (a) Define optical centre of a spherical lens.
would you place an object to get a
(b) You are given aconvex lens of focal length 30 cm. Where
diagram showing the
real, inverted and highly enlarged image of the object? Draw a ray
image formation.
should an object be placed so
(c) A concave lens has a focal length of 20 cm. At what distance
lens? (3)
that it forms an image at 15 cm away from the
32. (a) List two causes of hypermetropia.
its correction using
(b) Draw ray diagrams showing (i) a hypermetropic eye and (ii) (3)
suitable optical device.
this statement? (3)
33. (a) The refractive index of Ruby is 1.71. What is meant by
(b) The refractive index of some medium are given below:
Medium Refractive index
Crown glass 1.52
Water 1.33
Sapphire 1,77
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 (c) In which of the medium is the speed of light
(i)maximum (ii)minimum (ti) Calculate speed of light in sapphire.
Section-D
Question No. 34 to 36 are long answer questions
34. (a) A metal carbonate "X" reacting with acid gives a gas which, when passed through a
the carbonate back. On the other hand, a gas "G" obtained at the anode during solution " gives
electrolysis of brine is
passed on dry "y", and it gives a compound "2", used for disinfecting drinking water. Identity X,
Y, Gand
(b)What is aqua regia?
(5)
OR
(a) Name the compound used to soften hard
(b) Why does an water.Write its molecular formula.
aqueous solution of acid conduct electricity?
(C) Afew drops of phenolphthalein indicator were added to an
Now another unknown solution "B" was added to it drop unknown solution "A". It acquired pink color.
Predict the nature of A & B. bydrop and the solution becomes colorless.
(d) Match the following chemical compounds given in
Column (A) with their appropriate uses in Column ()
Column A
Column B
(A) Bleaching powder () Preparation of glass
(B) Baking soda (iü) Production of H2 and Cl2
(C) Washing soda (iii) Decolourisation
(D) Sodium chloride
(iv) Antacid
35. (a) Distinguish between hormonal
coordination in plants and animals.
(b) Which part of the brain is responsible
for (5)
(i) intelligence () riding a bicycle
(ii) vomiting (iv) controlling hunger
(c) How is brain and spinal-cord protected
against mechanical injuries?
OR
(a) What are tropic movements? Give an
example of a plant hormone which
(i) inhibits growth (ii) promotes cell division.
(b) Explain directional movement of a
tendril in pea plant in response to touch. Name the
responsible for this movement. hormone
36. (a) Define resistance of a conductor.
(b) State the factors on which resistance of a conductor
(c) Name the device which is often used to depends.
in an electric circuit.
change the resistance without changing the voltage source
(d) Calculate the resistance of 50cm length of wire of
cross sectional area 0.01mm² and of resistivity
5x108 m
OR (5)

(a) State Ohm's law

(b) Find the resistance of a resistor if it has a voltage of
(c) Awire of resistance 4 Q is stretched to twice Its 18V across it and a current of 6A flowing through it.
original
cross section gets halved, What will be the new resistance length. In the process of stretching, its area of
of the wire ?

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 SECTION -E
Question No. 37 to 39 are case-based/data -based
questions with 2to3short sub
parts.Internal choice is provided in one of these sub-parts.
37. Metals as we knoW, are very useful in all fields. industries in
particular. Non-metals are no less in any way.
Oxygen present in air is essential for breathing as well as for combustion. Non-metals form a large number
of compounds which are extremely useful, e.g., ammonia, nitric acid, sulphuric acid, etc. Non-metals are
tound to exist in three states of matter. Only solid non-metals are expected to be hard however, they have
low density and are brittle. They usually have low melting and boiling points and are poor conductors of
electricity.
(a) Give two examples of the metals that are poor conductors of heat. (1)
(b) Name a non-metal that exists in the liquid state at room temperature. (1)
(c) Asolution of CuSO4 was kept in an iron pot. After a few days, the iron pot was found to have several
holes in it. Give reason. Write the equation of the reaction involved. (2
OR
Aand
(C) An element "A" reacts with water to form a solution "B" which is used in whitewashing. ldentify
B. Give the reaction involved.

haemodialysis. It removes waste

38. The figure shown below represents a common type of dialysis called as
insufficiently removed by the kidney in
products from the blood, such as excess salts, and urea which are
patients with kidney failure. During the procedure, the patient's blood
is cleaned by filtration through a
returned to the blood of the patients. On the basis of
series of semi-permeable membranes before being
this, answer the following questions:

Line from artery

to punp
Tubing made ofa
selectivcly permcable
membranc

Dialysing
olutior
Lne from
apparatus
diang
Ued dalysing
to vcin olutkon with
olitor urca and
2cCSs salts
 (a) The haemodialyser has semi-permeable lining of tube. Why? (1)
OR
(a) What is the difference between fresh dialyzing solution and used dialyzing solution?
(b) Which function an artificial kidney cannot perform that normal kidneys can? (1
(c) Write one specific function each of the following parts in relation to normal kidneys: (2
() Renal Artery (ü) Collecting duct (ii) Glomerulus (iv) Tubular part of nephron
39. Light of allthe colours travel at the same speed in vacuum for all wavelengths. But in any transparent
medium (glass or water), the light of different colours travels at different speeds for different wavelengths,
which means that the refractive index of a particular medium is different for different wavelengths.
As there is a difference in their speeds, the light of different colours bend through different angles.
(a) Define refraction. (1)
(b) Among violet andred colour which deviates the least in glass medium? (1)
(c) State Snell's law. (2)
OR
(c) Draw a neat diagram to depict dispersion of light through a glass prism

2sley

po 26e24