THE ACHIEVERS SCHOOL, WARDHA ROAD,
NAGPUR.
PRELIMINARY EXAMINATION - 1 (2024 - 2025)
Class: 10 Sub: SCIENCE Total Marks : 80 Time : 3hr
Roll No. Date: 04/01/2025
Student’s Name:
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 some questions. 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 these questions
should in the range of 30 to 50 words.
v. Section C consists of 7 Short Answer type questions carrying 03 marks each. Answers to 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 to these
questions should be in the range of 80 to 120 words.
Section E consists of 3 source-based/case-based units of assessment of 04 marks each with sub-
parts
SECTION A
1) (1m
Which of the following are exothermic processes?
)
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
a) (i) and (ii) b) (ii) and (iii)
c) (i) and (iv) d) (ii) and (iv)
2) What type of chemical reaction takes place when electricity is passed through (1m
water?
a) Displacement b) Combination )
c) Decomposition d) Double displacement
3) Which one of the following salts does not contain water of crystallisation? (1m
)
a) Blue vitriol b) Baking soda
c) Washing soda d) Gypsum
1
4) (1m
The image shows some chemical reactions.
)
H +Cl → H Cl
2 H +O2 → 2 H 2 O
Which option identifies the reactants and products of the reactions?
a)
Reactants Products
H, Cl and HCl 2H, O2 and H2O
b)
Reactants Products
HCl and 2H2O H, Cl, 2H and O2
c)
Reactants Products
H, Cl, 2H and O2 HCl and 2H2O
d)
Reactants Products
2H, O2 and H2O H, Cl and HCl
5) Methyl orange is (1m
)
a) Pink in acidic medium, yellow in basic medium
b) Yellow in acidic medium, pink in basic medium
c) Colourless in acidic medium, pink in basic medium
d) Pink in acidic medium, colourless in basic medium.
6) On adding dilute HCl to copper oxide in a beaker, the solution turns blue-green (1m
due to formation of )
a) copper(II) hydroxide b) copper nitrate
c) copper sulphate d) copper (II) chloride
7) What happens when a pellet of sodium is dropped in water? (1m
)
a) It catches fire and forms oxide.
b) It catches fire and forms hydroxide
c) It absorbs heat and forms oxide.
d) It absorbs heat and forms hydroxide.
8) The genetic makeup of an organism is called its: (1m
)
a) Phenotype b) Genotype
c) Allele d) Chromosomes
9) What is the main purpose of respiration: (1m
)
a) To produce food b) To release oxygen
2
c) To release energy d) To absorb carbon dioxide
10) (1m
)
In the diagram the parts marked I, II & III are-
a) Cotyledon, plumule and radicle
b) Plumule, cotyledon and radicle
c) Plumule radicle and cotyledon
d) Radical , cotyledon and plumule
11) The main function of the plant hormone called abscisic acid is to: (1m
)
a) Increase the length of cells b) Promote cell division
c) Inhibit growth d) Promote growth of stem and
roots
12) Which of the following is not biodegradable (1m
)
a) leather b) detergents
c) paper d) cloth
13) In cattle, having horns is a recessive trait (h) to not having horns (H). When (1m
)
cattle with horns are crossed with cattle that do not have horns, the number of
offspring having horns was equal to those not having horns. Which of the
following is MOST LIKELY to be true?
a) Both parents are homozygous dominant.
b) One parent is homozygous dominant.
c) Both parents are heterozygous.
d) One parent is heterozygous.
14) Roots of the plants absorb water from the soil through the process of: (1m
)
a) diffusion b) transpiration
c) osmosis d) suction
15) The process of inducing a current in a coil of wire by placing it in a region of (1m
changing magnetic field is: )
a) Electrical effect b) Electromagnetic induction
c) Magnetic effect of current d) Heating effect of current
16) What is the current in a circuit if the charge passing each point is 20 C in 40 s? (1m
3
)
a) 0.5 C b) 0.5 A c) 0.2 C d) 0.2 A
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) : In esterification, carboxylic acid and alcohol reacts in the (1m
presence of acid to give ester. )
Reason (R) : Esterification is the reverse of saponification.
18) Assertion (A) : Polythene bags and plastic containers are non-biodegradable (1m
substances. )
Reason (R) : They can be broken down by microorganisms in natural simple
harmless substances.
19) Assertion(A) : The sex of a child is determined by the mother. (1m
Reason (R) : Humans have two types of sex chromosomes: XX and XY. )
20) Assertion (A): The strength of the magnetic field produced at the centre of a (1m
current-carrying circular coil increases on increasing the current flowing )
through the coil.
Reason (R): Magnetic field strength is inversely proportional to the current
flowing in the coil.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.
SECTION – B
Q. no. 21 to 26 are very short answer questions
21) Write equations for the reactions of (2m
i. iron with steam )
ii. calcium or potassium with water
OR
What are ionic compounds? List two properties of these compounds.
22) How are alveoli designed for exchange of gases? (2m
OR )
A plant X was enclosed in a glass jar with some lizards. A similar plant Y was
enclosed in another glass jar but without lizards. Both the jars are kept under
the same light conditions for a few hours. Which plant is likely to
photosynthesize more and why?
23) Explain feedback mechanism with an example. (2m
)
2
24) The refractive index of a medium x with respect to a medium y is and the (2m
3 )
4
4
refractive index of medium y with respect to medium z is . Find the refractive
3
index of medium z with respect to medium x. If the speed of light in medium x
is 3 × 10 8 ms -1, calculate the speed of light in medium y.
25) A person is unable to see clearly a poster fixed on a distant wall. He however (2m
sees it clearly when standing at a distance of about 2 m from the wall. )
a) Draw ray diagram to show the formation of image by his eye lens when he
is far away from the wall.
b) List two possible reasons of this defect of vision.
c) Draw ray diagram to show the correction of this defect using appropriate
lens.
26) A Mendelian experiment consisted of breeding pea plants bearing violet (2m
flowers with pea plants bearing white flowers. What will be the result of the F1 )
progeny?
SECTION - C
Q.no. 27 to 33 are short answer questions
27) A brown substance ’X’ on heating in air forms a substance ‘Y’. When hydrogen (3m
gas is passed over heated ‘Y’, it again changes back to X. )
a) Name the substance ‘X’ and ‘Y’
b) Name the chemical process occurring during both the changes.
c) Write the chemical equations involved in both the changes.
28) Differentiate between roasting and calcination process giving one example (3m
each )
29) a) What causes movement of food inside the alimentary canal? (3m
b) Why is small intestine in herbivores longer than in carnivores? )
c) What will happen if mucus is not secreted by the gastric glands?
OR
What is the advantage of having a four-chambered heart in birds and
mammals?
Explain double circulation.
30) Distinguish between real image and virtual image. (3m
)
31) Derive the relation between kilowatt hour and joule. (3m
)
32) i. A hot plate of an electric oven connected to a 220 V line has two resistance (3m
coils A and B, each of 24 Ω resistance, which may be used separately, in )
series, or in parallel. What are the currents in the three cases?
ii. Calculate the resistance of an electric bulb that allows a 10A current when
connected to a 220V power source?
33) Marked decline in the thickness of ozone layer was noticed in the 1980s. Why is (3m
this a cause of concern? Which human activity can be held accountable for this )
change? What is the possible effect of this on human health?
SECTION - D
Q.no. 34 to 36 are Long answer questions.
34) a) Write the name and structure of an aldehyde with three carbon atoms in its (5m
molecule. )
5
b) Draw the structure of butanoic acid and identify the functional group
present in it.
c) Draw the electron dot structure of C2H4
d) Define the term ‘isomers’
OR
Explain the following reactions with one example for each giving relevant
chemical equations:
a) Hydrogenation reaction
b) Oxidation reaction
c) Substitution reaction
d) Combustion reaction
e) Dehydration of Alcohol
35) a. Explain the role of placenta in the development of an embryo. (5m
b. What changes take place in uterus to receive a fertilized egg? )
OR
Why is vegetative propogation useful for some plants? What are the limitations
of this method?
36) Differentiate between a concave mirror and a convex mirror. (5m
OR )
a. Draw a ray diagram for showing the convergence of a parallel beam of light
by a concave mirror and mark the positions of pole and the centre of
curvature in it.
b. An object 4 cm in size is placed at 25 cm in front of a concave mirror of focal
length 15 cm. At what distance from the mirror should a screen be placed in
order to obtain a sharp image? Find the nature and size of the image.
c. List any two uses of a concave mirror.
SECTION - E
Q.no. 37 to 39 are case - based/data -based questions with 2 to 3 short
sub - parts. Internal choice is provided in one of these sub-parts
37) Ram and Asha were a married couple. They had four children - one of these (4m
children had sickle cell anemia whereas the other three children did not show )
symptoms. Ram and Asha did not show symptoms of sickle cell anaemia. The
trait for sickle cell anaemia is not linked to the sex chromosomes.
a) Is this disease caused by a dominant or recessive trait? (1)
b) Why is it dominant or recessive? (1)
c) If the child that had sickle cell anaemia got married to a person without a (2)
mutation in the sickle cell anaemia gene, what percentage of their children
would have sickle cell anaemia? Show the cross.
OR
Identify the genetic composition of the sickle cell anaemia trait in Asha and
Ram and use that to predict the genetic composition in the other four children
6
who did not show symptoms that Ram and Asha had.
38) When an object made of metal A is kept in air for a considerable time, it loses (4m
its shine and becomes almost black due to the formation of a layer of substance )
B. When an object made of another metal C is kept in damp air for a
considerable time, it gets covered with a green layer of substance D. Metal A is
the best conductor of electricity whereas metal C is the next best conductor of
electricity.
a) What is metal A?
b) What is metal C?
C) Name the substance B.
d) Name the substance D.
OR
d) What type of chemical can be used to remove the green layer from metal C
and clean it? Why?
39) A student was asked to perform an experiment to study the force on a current (4m
carrying conductor in a magnetic field. He took a small aluminium rod AB, a )
strong horse shoe magnet, some connecting wires, a battery and a switch and
connected them as shown. He observed that on passing current, the rod gets
displaced. On reversing the direction of current, the direction of displacement
also gets reversed. On the basis of your understanding of this phenomenon,
answer the following questions:
i. Why does the rod get displaced on passing current through it? (1)
ii. State the rule that determines the direction of the force on the conductor (1)
AB.
iii. a] If the U-shaped magnet is held vertically and the aluminium rod is (2)
suspended horizontally with its end B towards due north, then on passing
current through the rod from B to A as shown, in which direction will the rod
be displaced?
b] Name any two devices that use current carrying conductors and
magnetic field.
OR
Draw the pattern of magnetic field lines produced around a current carrying
straight conductor held vertically on a horizontal cardboard. Indicate the
direction of the field lines as well as the direction of current flowing through the (2)
conductor.
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