10th Science Quarterly Exam 2024-25 | Original Question Paper with Answer Key

Class 10 Science - Common Quarterly Examination 2024-25

Solved Question Paper

PART - I

Choose the correct answer. (12 x 1 = 12)

1. Impulse is equal to

• a) Rate of change of momentum
• b) Rate of force and time
• ⓒ Change of Momentum
• d) Rate of change of mass

2. Atomicity of Phosphorous is

• a) 4
• b) 3
• c) 6
• d) 7

3. Which one is referred as "Master Gland"?

• a) Pineal Gland
• ⓑ Pituitary Gland
• c) Thyroid Gland
• d) Adrenal Gland

4. In India domestic circuits are supplied with an alternating current of Potential

• a) 230 V
• ⓑ 220 V
• c) 240 V
• d) 230 V

5. Deliquescence is due to

• ⓐ Strong affinity to water
• b) Less affinity to water
• c) Strong hatred to water
• d) Inertness to water

6. The ____ Units form the backbone of the DNA

• a) 5 Carbon Sugar
• b) Phosphate
• c) Nitrogenous base
• ⓓ Sugar Phosphate

7. Which of the following lens would you prefer to use while reading small letters found in a dictionary?

• ⓐ A convex lens of Focal length 5 cm
• b) A concave lens of Focal length 5cm
• c) A convex lens of Focal length 10 cm
• d) A concave lens of Focal length 10 cm

8. Neon shows Zero electron affinity due to

• a) Stable arrangement of neutrons
• ⓑ Stable configuration of electrons
• c) Reduced size
• d) Increased density

9. ____ is an instrument which records the electrical impulses of brain

• a) ECG
• b) EGG
• ⓒ EEG
• d) EGE

10. "Heart of Heart" is called

• ⓐ SA node
• b) AV node
• c) Purkinje fibres
• d) Bundle of His

11. Nerve cells do not Possess

• a) Neurilemma
• ⓑ Sarcolemma
• c) Axon
• d) Dentrites

12. Across the period, ionic radii ____

• a) Increase and then Decrease
• b) Increases
• ⓒ Decreases
• d) Remains constant

PART - II

Answer any seven questions. Q.No. 22 is compulsory. (7 x 2 = 14)

13. Define: Co efficient of real expansion, and mention its Units.

Coefficient of real expansion is defined as the ratio of the true rise in the volume of the liquid per degree rise in temperature to its unit volume. The SI unit of coefficient of real expansion is the K^-1.

14. What is Rust? Give the equation for the Formulation of Rust.

When iron is exposed to moist air, it forms a layer of brown hydrated ferric oxide on its surface. This compound is known as rust and the phenomenon of formation of rust is known as rusting.

Equation: 4Fe + 3O₂ + xH₂O → 2Fe₂O₃.xH₂O (Rust).

15. Why is Sinoatrial node Called as Pacemaker of Heart.

Sinoatrial node is called the pacemaker of the heart because it is capable of initiating impulse, which can stimulate the heart muscles to contract.

16. Match the items in column I to items in Column II

Column I	Column II
i) Electric Current	a) Volt
ii) Potential difference	b) Ohm meter
iii) Specific resistance	c) Watt
iv) Electrical energy	d) Joule
	e) Ampere

Correct Matches:

• i) Electric Current - e) Ampere
• ii) Potential difference - a) Volt
• iii) Specific resistance - b) Ohm meter
• iv) Electrical energy - d) Joule

17. Why the Relative molecular mass has no Unit?

It is only a ratio.

18. What do you understand by the term Phenotype and Genotype?

The external expression of a particular trait is known as the phenotype.

The genetic expression of an organism is a genotype.

19. Difference between Systemic Circulation and Pulmonary Circulation?

Systemic circulation	Pulmonary circulation
In systemic circulation, the oxygenated blood entering the aorta from the left ventricles is carried by a network of arteries to the tissues.	In pulmonary circulation, the blood from the heart (right ventricle) is taken to the lungs by pulmonary artery.
The deoxygenated blood from the tissue is collected by veins and vena cava, emptied into the right atrium.	The oxygenated blood from lungs is emptied into the left auricle by the pulmonary veins.

20. While catching a cricket Ball, the Fielder lowers his hands backwards.Why?

While catching a cricket ball the fielder lowers his hands backwards, so increase the time during which the velocity of the cricket ball decreases to zero. Therefore the impact of force on the palm of the fielder will be reduced.

21. What is respiratory Quotient?

Respiratory quotient is the ratio of volume of carbon dioxide liberated and the volume of oxygen consumed during respiration. It is expressed as,

RQ = Volume of CO₂ liberated / Volume of O₂ consumed

22. Calculate the number of water Molecules present in one drop of water which weights 0.18g. (Compulsory)

Avagadro number = 6.023 x 10²³

Given mass = 0.18 g

Molecular weight of water (H₂O) = (2x1) + (1x16) = 2+16 = 18

Number of molecules = Avagadro number X (given mass / gram molecular mass)

= 6.023 x 10²³ X (0.18 / 18)

= 6.023 x 10²³ X 0.01

= 6.023 x 10²¹

PART - III

Answer any seven questions. Q.No. 32 is compulsory. (7 x 4 = 28)

23. a) Differentiate Mass and Weight (any two)

b) Write any two properties of Light

Light is a form of energy.

Light always travels along a straight line.

24. a) Why are traffic signals Red in Colour?

Red light has the highest wavelength. It is visible clearly from a long distance and is scattered the least by fog or smoke.

b) What is Power of Accommodation Eye?

The ability of the eye lens to focus nearby as well as the distant objects is called the power of accommodation of the eye.

25. a) Will the cool drinks give more fizz at the top of the hills or at the foot. Explain.

The cold drinks will give more fizz at the top of the hill, because, the fizz is created due to the excessive pressure released which is sealed inside the bottle for carbonation. At higher altitudes (top of the hills), the atmospheric pressure is lower, causing the dissolved CO₂ to come out of the solution more rapidly.

b) CaCO₃ → CaO + CO₂ i) How many moles of Calcium carbonate are involved in this reaction ii) How many moles of CO₂ are their in this equation

i) 1 mole of CaCO₃

ii) 1 mole of CO₂

26. Differentiate between hygroscopic substances and deliquescence substances.

27. a) Minerals in the plants are not lost, when the leaf falls. Give Reason.

Minerals are remobilised from older leaves to younger leaves before the leaf falls. This exchange takes place between xylem and phloem, ensuring essential nutrients are conserved by the plant.

b) Draw the structure of Human sperm and label the parts.

28. a) Write the Chargaff rule of DNA base pairing.

The rule states that in DNA the proportion of adenine is always equal to that of thymine and the proportion of guanine is always equal to that of cytosine. (A=T and G=C).

b) Why the mature RBC in Mammals do not have Cell Organelles?

The lack of Nucleus and other cell organelles in mature mammalian RBCs allows more space to carry oxygen.

29. The electronic configuration of metal 'A' is 2, 8, 18, 1 the metal 'A' with Con. H₂SO₄ forms C and D along with water. 'D' is a gaseous compound. Find A, B, C and D.

The metal 'A' with electronic configuration 2, 8, 18, 1 is Copper (Cu).

• (A) – Copper (Cu)
• (B) – Concentrated Sulphuric Acid (H₂SO₄)
• (C) – Copper Sulphate (CuSO₄)
• (D) – Sulphur dioxide (SO₂)

Reaction: Cu + 2H₂SO₄ (conc.) → CuSO₄ + SO₂ + 2H₂O

30. a) What is Guttation?

Guttation is a natural process in plants that involves the release of excess water, minerals, and chemicals from the tips or edges of leaves through special pores called hydathodes.

b) Where are Estrogens Produced? What is the role of Estrogens in the Human body?

Production: Oestrogen is produced by the Graafian follicles of the ovary.

Functions of oestrogens:

• It brings about the changes that occur during puberty.
• It initiates the process of oogenesis.
• It stimulates the maturation of ovarian follicles in the ovary.
• It promotes the development of secondary sexual characters (breast development, high pitched voice etc).

31. a) Identify whether the statement are True or False. Correct the False statement.

i) An anticoagulant present in the saliva of leech is called heparin.

False. Correct statement: An anticoagulant present in the saliva of leech is called hirudin.

ii) Cerebellum controls the voluntary actions of our body.

False. Correct statement: Cerebrum controls the voluntary actions of our body.

b) Define: Reflex arc

The path taken by nerve impulse to accomplish reflex action is called a Reflex arc.

32. Calculate the coefficient of Cubical expansion of Zine bar, whose volume is increased 0.25 m³ from 0.3m³ due to the change in temperature of 50k. (Compulsory)

Initial volume V0 = 0.25 m³

Final volume = 0.30 m³+0.25=0.55

Change in volume ΔV = 0.25 jim³

Temperature ΔT = 50K

PART - IV

Answer all the questions in detail. (3 x 7 = 21)

33. a) "Wearing helmet and fastening the seat belt is highly recommended, for safe Journey". Justify your answer using Newton's Laws of Motion.

(i) According to Newton's Second Law (F=ma), an unbalanced force is required to change the state of motion of a body. When a vehicle stops suddenly, due to inertia of motion, the passenger continues to move forward. A seat belt applies a force to the passenger to prevent them from colliding with the dashboard, reducing injury.

(ii) According to Newton's Third Law, for every action, there is an equal and opposite reaction. When you fall from a bike on the ground with a force equal to your mass and acceleration, the ground exerts an equal and opposite reacting force on your body. When you do not wear a helmet, this reacting force on the head can cause fatal head injuries. So it is important to wear a helmet for a safe journey.

b) State Newton's Third Law.

For every action there is an equal and opposite reaction.

c) Give any two examples for moment of a Couple.

Steering wheel of a car.

Turning of a screw driver.

Opening and closing of water tap.

(OR)

a) Differentiate series and Parallel circuit (any two)

b) State. Joule's law of Heating.

Joule's law of heating states that the heat produced in any resistor is:

• directly proportional to the square of the current passing through the resistor (H ∝ I²).
• directly proportional to the resistance of the resistor (H ∝ R).
• directly proportional to the time for which the current is passing through the resistor (H ∝ t).

Thus, H = I²Rt

c) What is the role of the Earthwire domestic circuits.

The main function of the earth wire is to prevent live wire from overloading and absorbs the excess electrons & flows to beneath the ground. It is a safety measure that provides a path for current to flow to the earth if there is a fault in an appliance. This prevents the electrical appliances from damage and absorbs the excess electricity, protecting users from electric shock.

34. a) Give the salient features of Modern atomic theory.

• An atom is no longer indivisible.
• Atoms of the same element may have different atomic mass (Isotopes).
• Atoms of different elements may have the same atomic masses (Isobars).
• Atoms of one element can be transmuted into atoms of other elements. In other words, an atom is no longer indestructible.
• Atoms may not always combine in a simple whole-number ratio.
• Atom is the smallest particle that takes part in a chemical reaction.
• The mass of an atom can be converted into energy [E = mc²].

b) Identify the bond between the 'H' and 'F' in HF Molecule

Ionic, because the electronegativity difference is more than 1.7.

c) Name the Acid that renders Aluminium Passive.

Dilute or concentrated nitric acid (HNO₃) renders aluminium passive. Because nitric acid does not attack aluminium but it renders aluminium passive due to the formation of an oxide film on its surface.

(OR)

a) What happens when MgSO₄.7H₂O is heated? Write the appropriate equation.

When Epsom salt (MgSO₄.7H₂O) crystals are gently heated, it loses seven water molecules and becomes anhydrous MgSO₄.

b) Write notes on Various features affecting solubility.

There are three main factors which affects the solubility of a solute. They are:

1. Nature of the solute and solvent : The nature of the solute and solvent plays an important role in solubility. The principle "like dissolves like" applies. Ionic compounds are soluble in polar solvents like water, and covalent compounds are soluble in non-polar solvents like ether, benzene, alcohol etc.
2. Effect of Temperature :
   • Solubility of solid in liquid : Generally solubility of a solid solute in a liquid increases with increase in temperature (Endothermic process). In an Exothermic process, solubility decreases with increase in temperature.
   • Solubility of Gases in liquid : Solubility of gases in liquid decreases with increase in temperature.
3. Effect of Pressure : Effect of pressure is observed only in the case of solubility of a gas in a liquid. When the pressure is increased, the solubility of a gas in liquid increases.

35. a) Luteal Phase of the Menstrual cycle is also called the secretory Phase. Give Reason.

During the Luteal phase of the menstrual cycle in the uterus, the hormone progesterone is produced by the ovaries. Progesterone and estrogen are secreted by the Corpus Luteum, which develops from the Graafian follicle after ovulation. Progesterone causes the uterine lining (endometrium) to thicken and secrete nutrients in preparation for a potential pregnancy. Because of these secretions, this phase is also called the secretory phase.

b) Define: Triple Fusion.

The fusion involving two polar nuclei and a sperm nucleus, that occurs in double fertilization in a seed plant and results in the formation of endosperm, is called the triple fusion.

c) Why family planning methods are not adopted by all the people of our country?

Family planning is a way of living that is adopted voluntary by couples on the basis of knowledge and responsible decision to promote the health and welfare of the family group and society. As it is voluntary, many people are not aware of the importance of family planning due to lack of education, social and religious beliefs, and limited access to healthcare services.

(OR)

a) List out the Parasitic adaptations of Leech.

• Blood is sucked by the pharynx.
• Anterior and Posterior Suckers are provided, by which the animal attaches itself to the body of the host.
• The three Jaws, inside the mouth, causes a painless Y – shaped wound in the skin of the host.
• The salivary glands produce Hirudin, which does not allow the blood to coagulate. So, the continuous supply of blood is maintained.
• Parapodia and Setae are absent.
• Blood is stored in the crop. It gives nourishment to the leech for several months. So there is no elaborate secretion of the digestive juices and enzymes.

b) What are the structures involved in the Protection of Brain.

Cranium (skull) and three connective tissue membrane meninges - Duramater, Arachnoid membrane and piamater protect the brain.