Standard 10 SCIENCE
Common First Mid Term Test - 2025 | Tirunelveli District
Time: 1.30 Hrs. | Marks: 50
Original Question Paper
- 9.8 dyne
- $9.8 \times 10^4$ N
- $98 \times 10^4$ dyne
- 980 dyne
- Newton's third law of motion
- Newton's law of gravitation
- Law of conservation of linear momentum
- Both a and c
- Convex lens
- Concave lens
- Convex mirror
- Bi-focal lenses
- positive
- negative
- either positive or negative
- zero
- 11.2 litre
- 5.6 litre
- 22.4 litre
- 44.8 litre
- Glucose
- Helium
- Carbon dioxide
- Hydrogen
- Atomic radii
- Ionic radii
- Electron affinity
- Electron negativity
- When ATP is converted to ADP
- When CO₂ is fixed
- When H₂O is splitted
- All of these
- Carbohydrate
- Ethyl alcohol
- Acetyl CoA
- Pyruvate
- Metameres (somites)
- Proglottids
- Strobila
- All the above
- Define inertia. Give its classification.
- State Snell's law.
- Define: Relative atomic mass
- Write the different types of isotopes of oxygen and its percentage abundance.
- What is rust? Give the equation for formation of rust.
- Write a short note on mesophyll.
- What is respiratory quotient?
- How is diastema formed in rabbit?
- A beam of light passing through a diverging lens of focal length 0.3m appear to be focused at a distance 0.2m behind the lens. Find the position of the object.
- Describe rocket propulsion.
- Differentiate the eye defects: Myopia and Hypermetropia
- Give the salient features of "Modern atomic theory".
-
- Draw and label the structure of oxysomes.
- What is photosynthesis and where in a cell does it occur?
- How does locomotion take place in leech?
- Calculate the gram molecular mass of the following: (i) CO₂ (ii) Ca₃(PO₄)₂
-
State and prove the law of conservation of linear momentum.
(OR)Derive the relationship between Relative molecular mass and vapour density.
-
Differentiate the following:
- Monocot root and Dicot root
- Aerobic and Anaerobic respiration
(OR)- Explain the male reproductive system of rabbit with a labelled diagram.
- Write the dental formula of rabbit.
Solutions
Explanation: One kilogram force (1 kgf) is the force due to gravity on a mass of 1 kg.
1 kgf = $1 \text{ kg} \times 9.8 \text{ m/s}^2 = 9.8$ N.
We know that 1 N = $10^5$ dyne.
Therefore, 9.8 N = $9.8 \times 10^5$ dyne = $98 \times 10^4$ dyne.
Explanation: Rocket propulsion is based on Newton's third law of motion (for every action, there is an equal and opposite reaction) and the law of conservation of linear momentum (the total momentum of the system remains constant in the absence of external forces).
Explanation: Presbyopia is the age-related loss of the eye's ability to focus on nearby objects. It is caused by the weakening of ciliary muscles and decreased flexibility of the eye lens. It is corrected using bi-focal lenses, which have both a convex part (for near vision) and a concave part (for distant vision).
Explanation: A convex lens can form both real, inverted images (magnification is negative) and virtual, erect images (magnification is positive). Therefore, its magnification can be either positive or negative depending on the object's position.
Explanation: According to Avogadro's hypothesis, one mole of *any* gas (monatomic, diatomic, etc.) at Standard Temperature and Pressure (S.T.P) occupies a volume of 22.4 litres.
Explanation: A triatomic molecule contains three atoms.
Carbon dioxide ($\text{CO}_2$) has one carbon atom and two oxygen atoms (1 + 2 = 3 atoms).
Glucose ($\text{C}_6\text{H}_{12}\text{O}_6$) is polyatomic. Helium (He) is monatomic. Hydrogen ($\text{H}_2$) is diatomic.
Explanation: Electron negativity is a measure of the ability of an atom in a chemical compound to attract the shared pair of electrons towards itself. It is a relative property and has no units, often measured on scales like the Pauling scale.
Explanation: During the light-dependent reactions of photosynthesis, water molecules ($\text{H}_2\text{O}$) are split in a process called photolysis. This process releases electrons, protons ($\text{H}^+$), and oxygen ($\text{O}_2$) as a byproduct.
Explanation: Anaerobic respiration is the breakdown of glucose in the absence of oxygen. In yeast and some plants, the end products are ethyl alcohol ($\text{C}_2\text{H}_5\text{OH}$), carbon dioxide, and a small amount of ATP. In animal muscle cells, the end product is lactic acid.
Explanation: The body of a leech is segmented, and these segments are called metameres or somites. This type of segmentation is known as metamerism.
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 by an external unbalanced force, is known as inertia.
Classification of Inertia: Inertia is classified into three types:
- Inertia of rest: The resistance of a body to change its state of rest. (e.g., A person standing in a bus falls backward when the bus suddenly starts).
- Inertia of motion: The resistance of a body to change its state of uniform motion. (e.g., An athlete runs a certain distance after reaching the finishing line).
- Inertia of direction: The resistance of a body to change its direction of motion. (e.g., When a car makes a sharp turn, the passengers tend to lean sideways).
Snell's law of refraction 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 for a given pair of media. This constant value is called the refractive index ($\mu$) of the second medium with respect to the first.
Mathematically, it is expressed as:
$$ \frac{\sin i}{\sin r} = \mu $$Relative Atomic Mass (RAM): The relative atomic mass of an element is defined as the ratio of the average mass of one atom of the element to 1/12th the mass of one atom of Carbon-12.
It is a dimensionless quantity, but for calculations, it is often expressed in atomic mass units (amu).
$$ \text{Relative Atomic Mass} = \frac{\text{Average mass of one atom of the element}}{\frac{1}{12} \times \text{mass of one atom of Carbon-12}} $$Oxygen has three stable isotopes. Their mass numbers and natural percentage abundance are:
- Oxygen-16 ($^{16}\text{O}$): 99.76%
- Oxygen-17 ($^{17}\text{O}$): 0.04%
- Oxygen-18 ($^{18}\text{O}$): 0.20%
Rust: Rust is a reddish-brown flaky substance formed on the surface of iron or its alloys when they are exposed to air (oxygen) and moisture for a prolonged period. Chemically, rust is hydrated iron(III) oxide ($\text{Fe}_2\text{O}_3 \cdot x\text{H}_2\text{O}$).
Equation for formation of rust:
$$ 4\text{Fe} + 3\text{O}_2 + x\text{H}_2\text{O} \rightarrow 2\text{Fe}_2\text{O}_3 \cdot x\text{H}_2\text{O} $$(Iron + Oxygen + Water $\rightarrow$ Hydrated Iron(III) Oxide (Rust))
Mesophyll is the ground tissue present between the upper and lower epidermis of a leaf. It is the primary site for photosynthesis. In dicot leaves, the mesophyll is differentiated into two distinct regions:
- Palisade Mesophyll (or Palisade Parenchyma): Located just below the upper epidermis, it consists of elongated, compactly arranged cells rich in chloroplasts. These cells are positioned to maximize light absorption for photosynthesis.
- Spongy Mesophyll (or Spongy Parenchyma): Located below the palisade layer, it consists of irregularly shaped cells with large intercellular air spaces. These spaces facilitate the exchange of gases (CO₂, O₂, water vapor) within the leaf.
Respiratory Quotient (RQ): The respiratory quotient is defined as the ratio of the volume of carbon dioxide ($\text{CO}_2$) evolved to the volume of oxygen ($\text{O}_2$) consumed during respiration over a period of time.
The value of RQ depends on the type of respiratory substrate being used (e.g., carbohydrates, fats, proteins).
$$ \text{RQ} = \frac{\text{Volume of } \text{CO}_2 \text{ liberated}}{\text{Volume of } \text{O}_2 \text{ consumed}} $$A diastema is a gap between the teeth. In a rabbit, the diastema is a prominent gap found between the incisors at the front of the jaw and the premolars at the back. This gap is formed due to the absence of canine teeth. The diastema helps the rabbit in mastication (chewing) of its food effectively by allowing the tongue to manipulate the food.
This is a numerical problem involving a diverging (concave) lens.
Given data:
- Type of lens: Diverging lens (Concave lens)
- Focal length (f) = -0.3 m (Focal length of a diverging lens is negative)
- Image distance (v) = -0.2 m (The image is virtual and formed on the same side as the object, so it is negative)
To find: Object distance (u)
Formula: We use the lens formula:
$$ \frac{1}{f} = \frac{1}{v} - \frac{1}{u} $$Calculation:
Rearranging the formula to solve for u:
$$ \frac{1}{u} = \frac{1}{v} - \frac{1}{f} $$Substituting the given values:
$$ \frac{1}{u} = \frac{1}{-0.2} - \frac{1}{-0.3} $$ $$ \frac{1}{u} = -\frac{1}{0.2} + \frac{1}{0.3} $$ $$ \frac{1}{u} = -\frac{10}{2} + \frac{10}{3} $$ $$ \frac{1}{u} = -5 + \frac{10}{3} $$Finding a common denominator (3):
$$ \frac{1}{u} = \frac{-15 + 10}{3} $$ $$ \frac{1}{u} = \frac{-5}{3} $$Therefore, the object distance u is:
$$ u = -\frac{3}{5} = -0.6 \text{ m} $$Result: The object is placed at a distance of 0.6 m (or 60 cm) from the optical center of the lens on the same side as the light source. The negative sign confirms that the object is placed to the left of the lens (by convention).
Rocket propulsion is a classic example of Newton's third law of motion and the law of conservation of linear momentum.
- Fuel and Oxidizer: Rockets carry their own fuel (propellant) and an oxidizer. When the fuel is burned in the combustion chamber, it produces a massive amount of hot gas at very high pressure and temperature.
- Ejection of Gas (Action): These hot gases are expelled at a very high velocity through a nozzle at the rear of the rocket. This ejection of mass in the downward direction constitutes the "action" force.
- Upward Thrust (Reaction): According to Newton's third law, for every action, there is an equal and opposite reaction. The downward-expelled gas exerts an equal and opposite force on the rocket, pushing it upwards. This upward force is called the "thrust".
- Conservation of Momentum: In the absence of external forces, the total momentum of the rocket-gas system remains constant. Before firing, the rocket is at rest, and the total momentum is zero. When the gas is ejected downwards with a certain momentum, the rocket gains an equal and opposite momentum in the upward direction to conserve the total momentum of the system. As more gas is expelled, the rocket's mass decreases, and it accelerates to higher speeds to maintain momentum conservation.
Thus, the combination of action-reaction forces and momentum conservation allows the rocket to accelerate and travel into space.
| Feature | Myopia (Short-sightedness) | Hypermetropia (Long-sightedness) |
|---|---|---|
| Definition | A condition where a person can see nearby objects clearly but cannot see distant objects clearly. | A condition where a person can see distant objects clearly but cannot see nearby objects clearly. |
| Image Formation | The image of a distant object is formed in front of the retina. | The image of a nearby object is formed behind the retina. |
| Causes |
|
|
| Correction | Corrected by using a concave lens, which diverges the light rays before they enter the eye. | Corrected by using a convex lens, which converges the light rays before they enter the eye. |
The salient features of the Modern Atomic Theory are:
- Atom is no longer indivisible: An atom is composed of subatomic particles: protons, neutrons, and electrons.
- Isotopes: Atoms of the same element can have different atomic masses. These are called isotopes (e.g., $^{12}\text{C}$, $^{13}\text{C}$, $^{14}\text{C}$).
- Isobars: Atoms of different elements can have the same atomic mass. These are called isobars (e.g., $^{40}\text{Ar}$, $^{40}\text{K}$, $^{40}\text{Ca}$).
- Atoms are not always combined in simple whole-number ratios: In some non-stoichiometric compounds, the ratio of atoms is not simple (e.g., in sucrose, $\text{C}_{12}\text{H}_{22}\text{O}_{11}$, the ratio C:H:O is not a simple whole number).
- Atom is the smallest particle that takes part in a chemical reaction: While atoms are divisible, they are the smallest unit that retains the chemical properties of an element and participates in chemical reactions.
- Mass can be converted into energy: The mass of an atom can be converted into energy according to Einstein's equation, $E=mc^2$. This is evident in nuclear reactions.
- Draw and label the structure of oxysomes.
- What is photosynthesis and where in a cell does it occur?
i) Structure of Oxysomes:
Oxysomes, also known as F₀ - F₁ particles or elementary particles, are found on the inner mitochondrial membrane. They are responsible for ATP synthesis.
The oxysome has three parts:
- Head (F₁ particle): A spherical part projecting into the mitochondrial matrix. It is the site of ATP synthesis.
- Stalk: Connects the head and the base.
- Base (F₀ particle): Embedded in the inner mitochondrial membrane. It acts as a proton channel.
ii) Photosynthesis and its Location:
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy. During this process, they use sunlight, water, and carbon dioxide to create their own food (glucose) and release oxygen as a byproduct.
Location: Photosynthesis occurs in specialized organelles within plant and algal cells called chloroplasts. Chloroplasts contain the green pigment chlorophyll, which captures light energy.
The leech exhibits two primary modes of locomotion:
-
Looping or Crawling Movement:
This is the most common mode of movement on a solid surface. It involves the use of its two suckers (anterior and posterior) and the contraction/relaxation of its body muscles.
- The leech fixes its posterior sucker firmly to the substratum.
- It then contracts its circular muscles and relaxes its longitudinal muscles, causing the body to extend and become long and thin.
- Next, it fixes its anterior sucker to the new position.
- It then releases the posterior sucker and contracts its longitudinal muscles, causing the body to shorten and arch up, forming a loop.
- The posterior sucker is brought forward, close to the anterior sucker.
- This cycle is repeated, allowing the leech to "crawl" forward.
-
Swimming Movement:
In water, the leech can swim actively. It flattens its body and performs graceful, wave-like undulations (up and down movements) to propel itself through the water.
To calculate the gram molecular mass, we sum the atomic masses of all atoms in the molecule.
(Given atomic masses: C = 12 u, O = 16 u, Ca = 40 u, P = 31 u)
(i) Carbon Dioxide ($\text{CO}_2$):
- The molecule contains 1 Carbon atom and 2 Oxygen atoms.
- Molecular Mass = (1 × Atomic mass of C) + (2 × Atomic mass of O)
- Molecular Mass = (1 × 12) + (2 × 16)
- Molecular Mass = 12 + 32 = 44 u
Therefore, the gram molecular mass of $\text{CO}_2$ is 44 g/mol.
(ii) Calcium Phosphate ($\text{Ca}_3(\text{PO}_4)_2$):
- The molecule contains 3 Calcium atoms, 2 Phosphorus atoms, and (4 × 2) = 8 Oxygen atoms.
- Molecular Mass = (3 × Atomic mass of Ca) + (2 × Atomic mass of P) + (8 × Atomic mass of O)
- Molecular Mass = (3 × 40) + (2 × 31) + (8 × 16)
- Molecular Mass = 120 + 62 + 128
- Molecular Mass = 310 u
Therefore, the gram molecular mass of $\text{Ca}_3(\text{PO}_4)_2$ is 310 g/mol.
Statement: The law of conservation of linear momentum states that if there is no external unbalanced force acting on a system of bodies, then the total linear momentum of the system remains constant.
Proof:
Consider two bodies, A and B, of masses $m_1$ and $m_2$, respectively. Let them be moving in the same direction along a straight line with initial velocities $u_1$ and $u_2$, where $u_1 > u_2$.
Before Collision:
- Momentum of body A = $p_A = m_1 u_1$
- Momentum of body B = $p_B = m_2 u_2$
- Total initial momentum of the system = $m_1 u_1 + m_2 u_2$
During Collision:
The bodies collide for a short time, $t$. During the collision, body A exerts a force $F_B$ on body B, and body B exerts a force $F_A$ on body A.
According to Newton's third law of motion, the force exerted by A on B is equal and opposite to the force exerted by B on A.
$$ F_A = -F_B $$After Collision:
Let their velocities after the collision be $v_1$ and $v_2$, respectively.
- Final momentum of body A = $m_1 v_1$
- Final momentum of body B = $m_2 v_2$
- Total final momentum of the system = $m_1 v_1 + m_2 v_2$
From Newton's second law, force is the rate of change of momentum.
- Force on body A ($F_A$) = Rate of change of momentum of A = $\frac{m_1 v_1 - m_1 u_1}{t}$
- Force on body B ($F_B$) = Rate of change of momentum of B = $\frac{m_2 v_2 - m_2 u_2}{t}$
Substituting these into the equation from Newton's third law ($F_A = -F_B$):
$$ \frac{m_1 v_1 - m_1 u_1}{t} = - \left( \frac{m_2 v_2 - m_2 u_2}{t} \right) $$Cancelling 't' from both sides:
$$ m_1 v_1 - m_1 u_1 = -(m_2 v_2 - m_2 u_2) $$ $$ m_1 v_1 - m_1 u_1 = -m_2 v_2 + m_2 u_2 $$Rearranging the terms to group initial and final momenta:
$$ m_1 v_1 + m_2 v_2 = m_1 u_1 + m_2 u_2 $$This equation shows that:
Total final momentum = Total initial momentum
Thus, the total linear momentum of the system is conserved in the absence of an external force. Hence, the law is proved.
Definitions:
- Relative Molecular Mass (M): It is defined as the ratio of the mass of one molecule of a gas or vapour to the mass of one atom of Hydrogen. (Historically, Hydrogen was the standard).
$$ M = \frac{\text{Mass of 1 molecule of the gas/vapour}}{\text{Mass of 1 atom of Hydrogen}} $$ - Vapour Density (VD): It is defined as the ratio of the mass of a certain volume of a gas or vapour to the mass of the same volume of Hydrogen, measured under the same conditions of temperature and pressure.
$$ \text{VD} = \frac{\text{Mass of a certain volume of gas/vapour}}{\text{Mass of the same volume of Hydrogen}} $$
Derivation using Avogadro's Law:
Avogadro's law states that equal volumes of all gases, under the same conditions of temperature and pressure, contain the same number of molecules.
Let's consider the 'certain volume' in the definition of Vapour Density to contain 'n' molecules. Therefore, the same volume of Hydrogen will also contain 'n' molecules.
So, we can rewrite the Vapour Density formula as:
$$ \text{VD} = \frac{\text{Mass of 'n' molecules of the gas/vapour}}{\text{Mass of 'n' molecules of Hydrogen}} $$We can cancel 'n' from the numerator and denominator:
$$ \text{VD} = \frac{\text{Mass of 1 molecule of the gas/vapour}}{\text{Mass of 1 molecule of Hydrogen}} $$We know that Hydrogen is a diatomic gas, meaning one molecule of Hydrogen contains two atoms of Hydrogen ($\text{H}_2$). So, Mass of 1 molecule of Hydrogen = 2 × Mass of 1 atom of Hydrogen.
Substituting this into the Vapour Density equation:
$$ \text{VD} = \frac{\text{Mass of 1 molecule of the gas/vapour}}{2 \times \text{Mass of 1 atom of Hydrogen}} $$Let's rearrange this equation:
$$ 2 \times \text{VD} = \frac{\text{Mass of 1 molecule of the gas/vapour}}{\text{Mass of 1 atom of Hydrogen}} $$From our definition of Relative Molecular Mass (M), the right-hand side of this equation is equal to M.
$$ 2 \times \text{VD} = M $$Conclusion:
The relationship between Relative Molecular Mass (M) and Vapour Density (VD) is:
Relative Molecular Mass = 2 × Vapour Density
- Monocot root and Dicot root
- Aerobic and Anaerobic respiration
a) Differentiating Monocot Root and Dicot Root
| Feature | Monocot Root | Dicot Root |
|---|---|---|
| Xylem Bundles | Polyarch (many xylem bundles, usually more than six). | Tetrarch (four xylem bundles). |
| Pith | Large and well-developed at the center. | Small or absent (inconspicuous). |
| Cambium | Absent, so there is no secondary growth. | Present between xylem and phloem, allowing for secondary growth. |
| Pericycle | Gives rise to lateral roots only. | Gives rise to lateral roots, cork cambium, and parts of the vascular cambium. |
| Example | Maize, Grass | Bean, Sunflower |
b) Differentiating Aerobic and Anaerobic Respiration
| Feature | Aerobic Respiration | Anaerobic Respiration |
|---|---|---|
| Oxygen Requirement | Requires oxygen. | Does not require oxygen. |
| Location in Cell | Occurs in cytoplasm (glycolysis) and mitochondria (Krebs cycle, ETC). | Occurs only in the cytoplasm. |
| Breakdown of Glucose | Complete breakdown of glucose into carbon dioxide and water. | Incomplete breakdown of glucose into ethyl alcohol (or lactic acid) and carbon dioxide. |
| End Products | Carbon dioxide ($\text{CO}_2$), water ($\text{H}_2\text{O}$), and ATP. | Ethyl alcohol and $\text{CO}_2$ (in yeast) or Lactic acid (in muscles), and ATP. |
| Energy Yield | High energy yield (approx. 36-38 ATP molecules per glucose molecule). | Low energy yield (only 2 ATP molecules per glucose molecule). |
- Explain the male reproductive system of rabbit with a labelled diagram.
- Write the dental formula of rabbit.
a) Male Reproductive System of Rabbit
The male reproductive system of a rabbit consists of a pair of testes, accessory glands, and ducts.
- Testes: These are the primary reproductive organs. They are ovoid in shape and are located outside the abdominal cavity in a pouch called the scrotal sac. The scrotal sac provides a lower temperature than the body, which is essential for sperm production (spermatogenesis). Testes produce sperm and the male sex hormone, testosterone.
- Epididymis: It is a long, coiled tube located on the surface of each testis. Sperm produced in the testes mature and are temporarily stored here.
- Vas Deferens (Sperm Duct): This is a tube that arises from the epididymis and ascends into the abdomen. It loops over the ureter and joins the urethra. Its function is to transport sperm from the epididymis to the urethra.
- Urethra: It is a common passage for both urine and semen. It extends through the penis to the exterior.
- Accessory Glands: These glands produce seminal fluid, which mixes with sperm to form semen. The fluid provides nourishment and a medium for sperm to swim. The accessory glands in a rabbit include:
- Prostate gland
- Cowper's gland (bulbourethral gland)
- Perineal gland
- Penis: It is the copulatory organ used to transfer semen into the female's reproductive tract during mating.
b) Dental Formula of Rabbit
The dental formula represents the number and type of teeth in one half of the upper and lower jaw. The types of teeth are incisors (I), canines (C), premolars (P), and molars (M).
A rabbit is a herbivore and lacks canine teeth. The dental formula for a rabbit is:
$$ \text{I} \frac{2}{1}, \text{C} \frac{0}{0}, \text{P} \frac{3}{2}, \text{M} \frac{3}{3} $$This can be written as: $$ \frac{2033}{1023} $$
Total number of teeth = (2 + 0 + 3 + 3) + (1 + 0 + 2 + 3) = 8 + 6 = 14 (in one half).
Total teeth in the rabbit = 14 × 2 = 28.