10th Science Quarterly Exam 2024 - Solved Question Paper
PART - I
Choose the best answer (12 X 1 = 12)
1.One kilogram force equal to
Answer: (c) 98 X 10⁴ dyne
2.Which of the following one is used in camera
Answer: (b) Convex lense
3.The value of universal gas constant
Answer: (d) 8.31 Jmole⁻¹K⁻¹
4.SI unit of resistance is
Answer: (c) ohm
5.Mass of 1 mole of Nitrogen atom is
Answer: (d) 14g
6.In modern periodic table the fourth group consist ........ number of elements.
Answer: (b) 18 (Note: The question likely meant the fourth period, which has 18 elements. Group 4 has 4 elements.)
7......... is an important metal to form Amalgam
Answer: (b) Hg
8.Which of the following is the universal solvent?
Answer: (c) Water
9......... is ATP factory of the cell
Answer: (c) Mitochondria
10.Vomiting centre is located in
Answer: (a) Medulla Oblongata
11.Which hormone is known as life "Saving hormone"
Answer: (c) Cortisol
12.Okazaki fragments are joined togather by ........
Answer: (b) DNA ligase
PART - II
Answer any seven questions. Question No. 22 is compulsory. (7 X 2 = 14)
13.Identify whether the statement are true (or) false. Correct the false statement.
(i) apparent weight of a person is always equal to him actual weight
False. Correction: The apparent weight of a person is not always equal to their actual weight. It can change depending on the acceleration of the person.
(ii) Momentum = m X a
False. Correction: Momentum (p) = mass (m) × velocity (v).
14.What are the causes of "Myopia"?
The two main causes of myopia (near-sightedness) are:
1. Lengthening of the eyeball.
2. Increase in the curvature of the eye lens, which reduces its focal length.
1. Lengthening of the eyeball.
2. Increase in the curvature of the eye lens, which reduces its focal length.
15.State the law of volume.
Gay-Lussac's Law (Law of Volume): When the pressure of a gas is kept constant, the volume of the gas is directly proportional to its absolute temperature (V ∝ T).
16.Give any two examples for heteroatomic molecules.
Two examples of heteroatomic molecules are:
1. Water (H₂O)
2. Carbon dioxide (CO₂)
1. Water (H₂O)
2. Carbon dioxide (CO₂)
17.Filling the blank.
(i) The Chief ore of Aluminium is ........
The Chief ore of Aluminium is Bauxite (Al₂O₃.2H₂O).
(ii) The Chemical name of rust is ........
The Chemical name of rust is hydrated ferric oxide (Fe₂O₃.xH₂O).
18.(i) What is the common step in aerobic and anaerobic pathyway? (ii) Glycolysis take place in ........?
(i) The common step in both aerobic and anaerobic pathways is Glycolysis.
(ii) Glycolysis takes place in the cytoplasm of the cell.
(ii) Glycolysis takes place in the cytoplasm of the cell.
19.Write the dental formula of rabbit.
The dental formula of a rabbit is I 2/1, C 0/0, P 3/2, M 3/3, which can be written as: 2033/1023.
20.Match the following.
| (i) Thyroxine | - Simple Goitre |
| (ii) Insulin | - Diabetes mellitus |
| (iii) Parathormone | - Tetany |
| (iv) ADH | - Diabetes insipidus |
21.Identify the part A, B and C.
[Image of a Neuron]
Based on the standard diagram of a neuron:
A: Cyton / Cell body
B: Nucleus
C: Dendrite
D: Axon
A: Cyton / Cell body
B: Nucleus
C: Dendrite
D: Axon
22.A solution was prepared by dissolving 25g of sugar in 100g of water. Calculate the mass percentage of solute.
Given:
Mass of solute (sugar) = 25 g
Mass of solvent (water) = 100 g
Calculation:
Mass of solution = Mass of solute + Mass of solvent = 25 g + 100 g = 125 g
Mass percentage of solute = (Mass of solute / Mass of solution) × 100
= (25 / 125) × 100 = 20%
Mass of solute (sugar) = 25 g
Mass of solvent (water) = 100 g
Calculation:
Mass of solution = Mass of solute + Mass of solvent = 25 g + 100 g = 125 g
Mass percentage of solute = (Mass of solute / Mass of solution) × 100
= (25 / 125) × 100 = 20%
PART - III
Answer any seven questions. Q. No. 32 is compulsory. (7 X 4 = 28)
23.Define Inertia. Give its classification.
Inertia: The inherent property of a body to resist any change in its state of rest or state of uniform motion, unless it is influenced upon by an external unbalanced force.
Classification:
1. Inertia of rest
2. Inertia of motion
3. Inertia of direction
Classification:
1. Inertia of rest
2. Inertia of motion
3. Inertia of direction
24.(i) Define - power of a lense. (ii) Write any two advantages of telescopes.
(i) Power of a lens: The power of a lens is defined as the degree of convergence or divergence of the light rays falling on it. It is the reciprocal of its focal length (P = 1/f). Its SI unit is Dioptre (D).
(ii) Advantages of telescopes:
1. They provide a magnified view of distant objects, allowing us to see details that are invisible to the naked eye.
2. They are used to observe celestial objects like stars, planets, galaxies, and nebulae for astronomical research.
(ii) Advantages of telescopes:
1. They provide a magnified view of distant objects, allowing us to see details that are invisible to the naked eye.
2. They are used to observe celestial objects like stars, planets, galaxies, and nebulae for astronomical research.
25.What is the advantage of LED TV over the normal TV?
Advantages of LED TV over normal (CRT) TV include:
• Brighter picture quality and better contrast.
• Thinner design and lighter weight.
• Lower power consumption, making them more energy-efficient.
• Longer lifespan and greater reliability.
• Brighter picture quality and better contrast.
• Thinner design and lighter weight.
• Lower power consumption, making them more energy-efficient.
• Longer lifespan and greater reliability.
26.(i) Differentiate Atom and molecules. (ii) What is rust? Give the equation for Formation of rust.
(i) Difference between Atom and Molecule:
(ii) Rust: Rust is a reddish-brown, flaky substance formed when iron or its alloys are exposed to oxygen and moisture for a long time. Chemically, it is hydrated ferric oxide.
Equation: 4Fe + 3O₂ + xH₂O → 2Fe₂O₃.xH₂O (Rust)
| Feature | Atom | Molecule |
|---|---|---|
| Definition | The smallest particle of an element that can take part in a chemical reaction. | The smallest particle of an element or compound that can exist freely. |
| Existence | Cannot exist freely (except noble gases). | Can exist in a free state. |
Equation: 4Fe + 3O₂ + xH₂O → 2Fe₂O₃.xH₂O (Rust)
27.In what way hygroscopic substance differ from deliquescent substance.
| Hygroscopic Substance | Deliquescent Substance |
|---|---|
| Absorbs moisture from the air but does not dissolve. | Absorbs enough moisture from the air to dissolve and form a solution. |
| Physical state does not change. | Changes from solid to liquid state. |
| Example: Concentrated H₂SO₄, Silica gel. | Example: NaOH, CaCl₂. |
28.List out the parasitic adaptation in leech
Parasitic adaptations in leech:
1. Suckers: Anterior and posterior suckers for firm attachment to the host.
2. Jaws: Three sharp jaws inside the mouth make a painless, Y-shaped incision.
3. Anticoagulant: Saliva contains hirudin, which prevents blood from clotting, ensuring a continuous supply.
4. Blood Storage: The crop is large and can store a huge volume of blood, which is digested slowly over months.
1. Suckers: Anterior and posterior suckers for firm attachment to the host.
2. Jaws: Three sharp jaws inside the mouth make a painless, Y-shaped incision.
3. Anticoagulant: Saliva contains hirudin, which prevents blood from clotting, ensuring a continuous supply.
4. Blood Storage: The crop is large and can store a huge volume of blood, which is digested slowly over months.
29.(i) Draw and label any four parts of neuron (ii) What is bolting? How can it be induced artificially?
(i) Diagram of a Neuron:
(ii) Bolting: Bolting is the premature elongation of the stem and flowering in biennial plants, typically induced by specific environmental conditions like long days or cold temperatures.
Artificial Induction: It can be artificially induced by the application of the plant hormone gibberellin.
[Diagram of a Neuron showing: 1. Cyton (Cell Body), 2. Nucleus, 3. Dendrites, 4. Axon]
(ii) Bolting: Bolting is the premature elongation of the stem and flowering in biennial plants, typically induced by specific environmental conditions like long days or cold temperatures.
Artificial Induction: It can be artificially induced by the application of the plant hormone gibberellin.
30.(i) Why is the sinoatrial node called the pacemaker of heart. (ii) Define reflex arc.
(i) SA node as pacemaker: The sinoatrial (SA) node is called the pacemaker because it has the unique ability to self-generate electrical impulses at the highest rate in the heart. These impulses initiate and regulate the rhythmic contractions of the heart muscle, setting the pace for the entire heartbeat.
(ii) Reflex arc: The pathway along which nerve impulses are carried from a receptor to an effector during a reflex action. It consists of a receptor, sensory neuron, interneuron (in spinal cord), motor neuron, and an effector (muscle or gland).
(ii) Reflex arc: The pathway along which nerve impulses are carried from a receptor to an effector during a reflex action. It consists of a receptor, sensory neuron, interneuron (in spinal cord), motor neuron, and an effector (muscle or gland).
31.(i) Define - triple fusion (ii) What are Okazaki fragments?
(i) Triple Fusion: It is the process in angiosperms where one male gamete fuses with the diploid secondary nucleus (formed from two polar nuclei) inside the embryo sac. This fusion results in the formation of a triploid (3n) Primary Endosperm Nucleus (PEN), which develops into the endosperm.
(ii) Okazaki Fragments: They are short, newly synthesized DNA fragments that are formed on the lagging strand during DNA replication. These fragments are later joined together by the enzyme DNA ligase to form a continuous strand.
(ii) Okazaki Fragments: They are short, newly synthesized DNA fragments that are formed on the lagging strand during DNA replication. These fragments are later joined together by the enzyme DNA ligase to form a continuous strand.
32.A torch bulb is rated 3V and 600m A calculate. a) power b) resistance
Given: Voltage (V) = 3V, Current (I) = 600 mA = 0.6 A
a) Power (P):
P = V × I
P = 3V × 0.6A = 1.8 W
b) Resistance (R):
R = V / I (from Ohm's Law)
R = 3V / 0.6A = 5 Ω
a) Power (P):
P = V × I
P = 3V × 0.6A = 1.8 W
b) Resistance (R):
R = V / I (from Ohm's Law)
R = 3V / 0.6A = 5 Ω
PART - IV
Answer all the questions. Draw diagrams wherever necessary. (3 X 7 = 21)
33.(i) Describe rocket propulsion. (ii) Differentiate convex lense and concavel lense.
(i) Rocket Propulsion:
Rocket propulsion is based on the law of conservation of linear momentum and Newton's third law of motion.
Rocket propulsion is based on the law of conservation of linear momentum and Newton's third law of motion.
- In a rocket, fuel and oxidizer (propellants) are burnt in a combustion chamber, producing a large quantity of hot gases at high pressure.
- These gases are expelled at a very high velocity through a nozzle at the rear of the rocket. This constitutes the 'action'.
- According to Newton's third law, the escaping gases exert an equal and opposite force on the rocket, known as the 'reaction'. This reaction force, or thrust, pushes the rocket forward (upward).
- As the rocket's mass decreases due to the ejection of gases, its velocity increases to conserve the total momentum of the system.
| Feature | Convex Lens | Concave Lens |
|---|---|---|
| Shape | Thicker at the center and thinner at the edges. | Thinner at the center and thicker at the edges. |
| Action on Light | It is a converging lens; it converges parallel light rays. | It is a diverging lens; it diverges parallel light rays. |
| Image Formed | Forms real and inverted images (mostly), and one virtual and erect image. | Always forms virtual, erect, and diminished images. |
| Used to Correct | Hypermetropia (long-sightedness). | Myopia (near-sightedness). |
OR
(i) State Ohm's law. (ii) Derive the ideal gas equation.
(i) Ohm's Law: At a constant temperature, the steady current (I) flowing through a conductor is directly proportional to the potential difference (V) across its ends. Mathematically, V ∝ I, or V = IR, where R is the constant of proportionality called resistance.
(ii) Derivation of Ideal Gas Equation: The ideal gas equation is derived by combining three gas laws:
V ∝ (1/P) × T × n
V ∝ nT/P
V = R (nT/P), where R is the universal gas constant.
Rearranging the equation, we get the ideal gas equation: PV = nRT
(ii) Derivation of Ideal Gas Equation: The ideal gas equation is derived by combining three gas laws:
- Boyle's Law: At constant temperature (T) and number of moles (n), the volume (V) of a gas is inversely proportional to its pressure (P).
V ∝ 1/P --- (1) - Charles's Law: At constant pressure (P) and number of moles (n), the volume (V) of a gas is directly proportional to its absolute temperature (T).
V ∝ T --- (2) - Avogadro's Law: At constant temperature (T) and pressure (P), the volume (V) of a gas is directly proportional to the number of moles (n).
V ∝ n --- (3)
V ∝ (1/P) × T × n
V ∝ nT/P
V = R (nT/P), where R is the universal gas constant.
Rearranging the equation, we get the ideal gas equation: PV = nRT
34.(i) Write value of Avogadro's number. (ii) State Avogadro hypothesis. (iii) Write any four application of Avogadro's law.
(i) Avogadro's number (Nₐ): The value is 6.023 x 10²³ mol⁻¹.
(ii) Avogadro's Hypothesis: It states that equal volumes of all gases under the same conditions of temperature and pressure contain an equal number of molecules.
(iii) Four Applications of Avogadro's Law:
(ii) Avogadro's Hypothesis: It states that equal volumes of all gases under the same conditions of temperature and pressure contain an equal number of molecules.
(iii) Four Applications of Avogadro's Law:
- It helps in explaining Gay-Lussac's law of gaseous volumes.
- It is used to determine the atomicity (number of atoms in a molecule) of gases.
- It helps in determining the molecular formula of a gaseous compound.
- It establishes the relationship between molecular mass and vapour density of a gas (Molecular Mass = 2 × Vapour Density).
OR
Write notes on various factors affecting solubility.
Factors Affecting Solubility:
1. Nature of the Solute and Solvent:- This is governed by the principle "like dissolves like".
- Polar solutes (e.g., sodium chloride) dissolve in polar solvents (e.g., water).
- Non-polar solutes (e.g., grease) dissolve in non-polar solvents (e.g., ether, CCl₄).
- Solids in Liquids: For most solids, solubility increases with an increase in temperature as the dissolution process is endothermic (absorbs heat). For a few substances (e.g., cerium sulphate), solubility decreases as temperature increases (exothermic dissolution).
- Gases in Liquids: The solubility of a gas in a liquid decreases with an increase in temperature. This is why boiled water has less dissolved oxygen.
- Solids in Liquids: The effect of pressure on the solubility of solids in liquids is negligible.
- Gases in Liquids: The solubility of a gas in a liquid increases with an increase in pressure (Henry's Law). This is why carbonated drinks are bottled under high pressure.
35.(i) What is respiratory quotient. (ii) Write the physiological effect of gibberlins.
(i) Respiratory Quotient (RQ): The Respiratory Quotient is the ratio of the volume of carbon dioxide evolved to the volume of oxygen consumed during respiration.
RQ = Volume of CO₂ evolved / Volume of O₂ consumed.
The value of RQ depends on the type of respiratory substrate used (e.g., for carbohydrates, RQ is 1).
(ii) Physiological Effects of Gibberellins:
RQ = Volume of CO₂ evolved / Volume of O₂ consumed.
The value of RQ depends on the type of respiratory substrate used (e.g., for carbohydrates, RQ is 1).
(ii) Physiological Effects of Gibberellins:
- Stem Elongation: They cause an extraordinary elongation of the stem, especially in genetically dwarf plants.
- Bolting: They promote bolting (premature flowering) in biennial plants like beet and cabbage.
- Parthenocarpy: They induce the development of seedless fruits (parthenocarpy) in plants like tomatoes.
- Breaking Dormancy: They are effective in breaking the dormancy of buds and seeds.
OR
(i) What is transpiration? (ii) Explain the structure of Chromosomes.
(i) Transpiration: Transpiration is the biological process of water loss in the form of water vapor from the aerial parts of a plant, primarily through small pores called stomata located on the leaves.
(ii) Structure of a Chromosome:
(ii) Structure of a Chromosome:
[Diagram of a Chromosome showing Chromatids, Centromere, and Telomeres]
A chromosome is a thread-like structure found inside the nucleus of eukaryotic cells. A well-defined chromosome can be observed during cell division.
- Chromatids: A chromosome consists of two identical, symmetrical strands called sister chromatids.
- Centromere: The sister chromatids are held together by a primary constriction called the centromere. The centromere is the point of attachment for spindle fibers during cell division.
- Telomere: The ends of the chromosome are called telomeres. They have a unique polarity and prevent the ends of chromosomes from sticking together.
- Secondary Constriction: Some chromosomes may have a secondary constriction at any point, which is useful in identifying a specific chromosome.
- Satellite: A knob-like structure beyond the secondary constriction is called a satellite. Chromosomes with satellites are called SAT chromosomes.