10th Science Quarterly Exam Question Paper 2024 with Solutions - Tenkasi District

Part - I

Choose the correct answer: 12x1=12

1) The unit of 'g' is ms⁻². It can be also expressed as

a) Cm S⁻¹ b) N Kg⁻¹ c) Nm² Kg⁻¹ d) Cm² S⁻²

Answer: b) N Kg⁻¹

2) Magnification of convex lens is ....................

a) positive b) negative c) either positive or negative d) zero

Answer: c) either positive or negative

3) SI unit of electrical resistivity is ....................

a) Ohm b) Ohm meter c) Joule d) Watt

Answer: b) Ohm meter

4) 1 mole of any substance contains .................... molecules

a) 6.023 × 10²³ b) 6.023 × 10⁻²³ c) 3.0115 × 10²³ d) 12.046 × 10²³

Answer: a) 6.023 × 10²³

5) .................... is an important metal to form amalgam.

a) Ag b) Hg c) Mg d) Al

Answer: b) Hg

6) The chemical formula for blue vitriol is ....................

a) CaSO₄. 2H₂O b) CaSO₄. 5H₂O c) CuSO₄. 2H₂O d) CuSO₄. 5H₂O

Answer: d) CuSO₄. 5H₂O

7) The xylem and phloem arranged side by side on same radius is called ....................

a) radial b) amphivasal c) conjoint d) None of these

Answer: c) conjoint

8) Mammals are .................... animals

a) Cold blooded b) Warm blooded c) Poikilothermic d) All the above

Answer: b) Warm blooded

9) Life span of platelets is ....................

a) 8 - 10 days b) 75 days c) 120 days d) 175 days

Answer: a) 8 - 10 days

10) Which one is referred as "Master Gland"?

a) Pineal gland b) Pituitary gland c) Thyroid gland d) Adrenal gland

Answer: b) Pituitary gland

11) Estrogen is secreted by ....................

a) anterior pituitary b) primary follicle c) Graffian follicle d) Corpus Luteum

Answer: c) Graffian follicle

12) Identify Dihybrid ratio in F₂ generation

a) 9 : 3 : 3 : 1 b) 9 : 1 : 3 : 1 c) 9 : 1 : 3 : 3 d) 1 : 2 : 1

Answer: a) 9 : 3 : 3 : 1

Part - II

Answer any 7 questions: Q.No. 22 is compulsory. 7x2=14

13) State Snell's law

Snell's law states that the ratio of the sine of the angle of incidence (i) to the sine of the angle of refraction (r) is a constant, which is equal to the refractive index of the second medium with respect to the first medium.
Mathematically, sin(i) / sin(r) = constant = μ

14) Define one calorie

One calorie is defined as the amount of heat energy required to raise the temperature of 1 gram of water by 1°C.

15) Give any two examples for heterodiatomic molecules

Two examples of heterodiatomic molecules (molecules made of two different atoms) are:

• Hydrogen Chloride (HCl)
• Carbon Monoxide (CO)

16) State whether True or False. If false write the correct statement

i) An alloy is a heterogeneous mixture of metals

ii) All ores are minerals; but all minerals cannot be called as ores

i) False.

Correct Statement: An alloy is a homogeneous mixture of two or more metals, or a metal and a non-metal.

ii) True.

17) Write the reaction for photosynthesis

The balanced chemical equation for photosynthesis is:
6CO₂ + 6H₂O → (in the presence of Sunlight and Chlorophyll) → C₆H₁₂O₆ + 6O₂

18) Write the dental formula of rabbit

The dental formula of a rabbit is: I 2/1, C 0/0, PM 3/2, M 3/3

19) What is the important of valves in the heart?

The valves in the heart are crucial for ensuring unidirectional blood flow. They open to allow blood to pass from one chamber to another and close to prevent the backflow of blood. This maintains the efficiency of the circulatory system.

20) Define reflex arc

A reflex arc is the neural pathway that controls a reflex action. It is the path along which nerve impulses are carried from a receptor to an effector to bring about a quick, involuntary response to a stimulus.

21) Draw and Label the parts of Gynoecium

The gynoecium is the female reproductive part of a flower. Its main parts are:

• Stigma: The receptive tip, responsible for receiving pollen.
• Style: The stalk that connects the stigma to the ovary.
• Ovary: The enlarged basal portion containing ovules.

22) (Compulsory) Calculate total resistance in the circuit

The two resistors, R₁ = 5 Ω and R₂ = 10 Ω, are connected in parallel.
The formula for total resistance (Rp) in a parallel circuit is:
1/Rp = 1/R₁ + 1/R₂
Substituting the values:
1/Rp = 1/5 + 1/10
Taking the LCM (10):
1/Rp = (2 + 1) / 10 = 3/10
Therefore, the total resistance is:
Rp = 10/3 Ω ≈ 3.33 Ω

Part - III

Answer any 7 questions: Q.No. 32 is compulsory. 7x4=28

23) Differentiate mass and weight

Property	Mass	Weight
Definition	It is the quantity of matter contained in a body.	It is the gravitational force exerted on a body due to Earth's gravity.
Nature	It is a scalar quantity.	It is a vector quantity.
Variation	It is constant everywhere.	It varies from place to place.
SI Unit	kilogram (kg)	newton (N)

24) a) Why does the sky appear in blue colour? b) State Boyle's Law

a) Why the sky appears blue:

The blue color of the sky is due to a phenomenon called Rayleigh scattering. When sunlight enters the Earth's atmosphere, the gases and particles in the air scatter the light in all directions. Blue light is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

b) Boyle's Law:

Boyle's Law states that for a fixed mass of an ideal gas at constant temperature, the pressure of the gas is inversely proportional to its volume.
Mathematically, P ∝ 1/V or PV = constant

29) a) What is bolting? b) Match the following

a) What is bolting?

Bolting is the premature production of a flowering stem on agricultural and horticultural crops before the crop is ready for harvest. This phenomenon is often induced by stress factors like changes in temperature or day length. It makes the crop inedible or reduces its quality.

b) Match the following:

Column - I	Column - II
i) Nissl's granules	Cyton
ii) Hypothalamus	Fore brain
iii) Cerebellum	Hindbrain
iv) Schwann cell	Peripheral Nervous system

32) (Compulsory) 16 grams of NaOH is dissolved in 100 grams of water at 25°C to form a saturated solution. Find the mass percentage of solute

Given:

• Mass of solute (NaOH) = 16 g
• Mass of solvent (water) = 100 g

First, calculate the total mass of the solution:

Mass of solution = Mass of solute + Mass of solvent
Mass of solution = 16 g + 100 g = 116 g

Now, calculate the mass percentage of the solute:

Mass Percentage = (Mass of solute / Mass of solution) × 100%
Mass Percentage = (16 / 116) × 100%
Mass Percentage = 0.1379 × 100%
Mass Percentage ≈ 13.79%

Part - IV

Answer all the questions. Draw diagram wherever necessary. 3x7=21

33) a) State and prove the Law of conservation of Linear momentum

a) Law of Conservation of Linear Momentum:

Statement: In the absence of an external unbalanced force, the algebraic sum of the momentum of a system of colliding objects remains constant.

Proof:

Consider two bodies, A and B, with masses m₁ and m₂ moving in a straight line with initial velocities u₁ and u₂, respectively. Let's assume u₁ > u₂. They collide for a short time 't' and then separate with final velocities v₁ and v₂.

• Force on body B by A (Fₐ): According to Newton's second law, the force is the rate of change of momentum.
  Fₐ = m₂(v₂ - u₂) / t
• Force on body A by B (Fᵦ): Similarly, the force exerted by body B on A is:
  Fᵦ = m₁(v₁ - u₁) / t

According to Newton's third law of motion, the force exerted by body A on B is equal and opposite to the force exerted by body B on A.

Fₐ = -Fᵦ
m₂(v₂ - u₂) / t = - [m₁(v₁ - u₁) / t]

Cancelling 't' on both sides:

m₂(v₂ - u₂) = -m₁(v₁ - u₁)
m₂v₂ - m₂u₂ = -m₁v₁ + m₁u₁

Rearranging the equation to group initial and final momenta:

m₁v₁ + m₂v₂ = m₁u₁ + m₂u₂

This shows that the Total momentum after collision = Total momentum before collision. Hence, the law of conservation of linear momentum is proved.

(OR)

a) Derive the ideal gas equation b) State Ohm's law

a) Derivation of the Ideal Gas Equation:

The ideal gas equation is derived by combining three gas laws:

1. 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 (constant T, n)
2. 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 (constant P, n)
3. 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 (constant T, P)

Combining these three laws, we get:

V ∝ (1/P) × T × n
V ∝ nT/P

This can be written as:

V = R (nT/P)
where R is the constant of proportionality, known as the Universal Gas Constant.

Rearranging the equation, we get the Ideal Gas Equation:

PV = nRT

b) Ohm's Law:

Ohm's law states that at a constant temperature, the steady current (I) flowing through a conductor is directly proportional to the potential difference (V) between its ends.
Mathematically, I ∝ V or V ∝ I.
This can be written as V = IR, where R is the constant of proportionality called Resistance.

35) a) What is respiratory quotient? b) With a neat labelled diagram explain the structure of a neuron

a) Respiratory Quotient (RQ):

Respiratory Quotient is the ratio of the volume of carbon dioxide (CO₂) evolved to the volume of oxygen (O₂) consumed during respiration.
RQ = Volume of CO₂ evolved / Volume of O₂ consumed
The value of RQ depends on the type of respiratory substrate being used. For carbohydrates, RQ is 1; for fats, it is less than 1; and for proteins, it is also less than 1.

b) Structure of a Neuron:

A neuron is the structural and functional unit of the nervous system. It consists of three main parts:

1. Cyton (Cell Body or Soma): It is the main part of the neuron, containing a large nucleus, cytoplasm (neuroplasm), and other cell organelles like mitochondria. It also contains characteristic granular bodies called Nissl's granules.
2. Dendrites: These are short, branched processes that arise from the cyton. They receive nerve impulses from other neurons and transmit them towards the cyton.
3. Axon: This is a single, long, slender projection that arises from the cyton. It transmits nerve impulses away from the cell body to another neuron or an effector organ (like a muscle or gland). The axon is covered by a protective sheath called the myelin sheath (formed by Schwann cells), which is interrupted at intervals called Nodes of Ranvier. The end of the axon branches into terminal buttons or synaptic knobs.

Figure: Structure of a Neuron

(OR)

a) With a neat labelled diagram describe the parts of a typical angiospermic ovule b) What are Okazaki fragments?

a) Structure of an Angiospermic Ovule:

The ovule is the structure within the ovary that contains the female reproductive cell and develops into a seed after fertilization. A typical angiospermic ovule consists of the following parts:

• Funiculus: The stalk that attaches the ovule to the placenta in the ovary.
• Hilum: The point where the body of the ovule fuses with the funiculus.
• Integuments: One or two protective outer layers of the ovule.
• Micropyle: A small opening at the apex of the integuments through which the pollen tube usually enters.
• Chalaza: The basal part of the ovule, opposite to the micropyle.
• Nucellus: A mass of parenchymatous tissue inside the integuments that encloses the embryo sac and provides nourishment.
• Embryo Sac (Female Gametophyte): It is located within the nucellus and contains the egg apparatus (one egg cell and two synergids), three antipodal cells at the chalazal end, and a central cell with two polar nuclei.

Figure: Structure of an Ovule

b) What are Okazaki fragments?

Okazaki fragments are short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication. Because DNA polymerase can only synthesize DNA in the 5' to 3' direction, replication on the lagging strand (which runs 3' to 5') is discontinuous. These short fragments are later joined together by the enzyme DNA ligase to form a continuous strand.