UP Board Class 10 Science Question Paper 2024 (Code 824 IM) Available : Download Solution PDf With Answer Key

In a concave mirror, when a ray of light passes through the focus, it reflects and follows its original path. After reflection, the ray intersects the principal axis at the centre of curvature.
Quick Tip: When a ray passes through the focus of a concave mirror, it reflects and retraces its path, intersecting the principal axis at the centre of curvature.

A convex lens is used to produce a virtual, erect, and magnified image of an object when it is placed between the focal point and the lens. This positioning leads to the formation of a magnified and virtual image.
Quick Tip: When the object is closer than the focal point of a convex lens, the image formed is virtual, erect, and magnified.

The focal length of the eye lens is adjusted by the ciliary muscles. These muscles contract or relax to alter the shape of the lens, enabling the eye to focus on objects at varying distances. The iris regulates the amount of light entering the eye but does not influence the focal length.
Quick Tip: Ciliary muscles play a crucial role in accommodation, changing the focal length of the eye lens for clear vision.

The blue color of the clear sky results from the scattering of sunlight by molecules and tiny particles in the atmosphere. This phenomenon, known as Rayleigh scattering, scatters shorter wavelengths of light (blue) more efficiently than longer wavelengths (red).
Quick Tip: Rayleigh scattering is responsible for the blue sky, as shorter wavelengths of light (blue) are scattered more than longer wavelengths.

Using the formula for electrical power, \(P = \frac{V^2}{R}\), where \(P\) represents power, \(V\) represents voltage, and \(R\) represents resistance, we can calculate the resistance as follows: \[ R = \frac{V^2}{P} = \frac{220^2}{440} = 110 \, ohms. \]
Quick Tip: To find the resistance of an electric bulb, use the formula \( R = \frac{V^2}{P} \), where \(V\) is the voltage and \(P\) is the power.

(1) The symbol represents a variable resistance.

(2) The symbol represents an ammeter.

(3) The symbol represents an electric cell.

(4) The symbol represents a wire crossing.
Quick Tip: Make sure you are familiar with standard electrical circuit symbols to easily recognize and match them.

When a current-carrying solenoid is suspended freely, it aligns with the Earth's magnetic field, which runs in the north-south direction. This is the reason why the solenoid always settles in the north-south orientation.
Quick Tip: The Earth's magnetic field plays a key role in determining the orientation of a freely suspended current-carrying solenoid.

Mercury is the only metal that exists in liquid form at room temperature. In contrast, the other metals—Magnesium, Copper, and Aluminium—remain solid at room temperature.
Quick Tip: Mercury is the only metal that exists as a liquid at room temperature.

When an acid reacts with a base, the usual products formed are salt and water. This process is referred to as a neutralization reaction.
Quick Tip: Neutralization reactions always produce salt and water.

This reaction is a decomposition reaction, as one reactant (calcium carbonate) breaks down into two products: calcium oxide and carbon dioxide.
Quick Tip: In a decomposition reaction, a single reactant breaks down into two or more products.

Carbon (C) possesses the property of catenation, which allows it to form long chains or rings by bonding with other carbon atoms.
Quick Tip: Catenation is the ability of an element to form long chains or rings, and carbon is the most well-known element with this property.

An alkyne is defined by the presence of a triple bond between two carbon atoms. In this case, CH\(_3\)-C≡C-H contains a triple bond, classifying it as an alkyne. The other options do not have triple bonds.
Quick Tip: In alkynes, the triple bond between two carbon atoms is a distinguishing feature.

Ethanol is commonly used both as a fuel and in medicine, thanks to its antiseptic and solvent properties. It is a key ingredient in alcoholic beverages, and is also used in thermometers and as an additive in fuels.
Quick Tip: Ethanol has multiple uses in medicine, fuel, and as a solvent due to its properties.

The nephron is the functional unit of the kidney, responsible for filtration, reabsorption, and secretion during the excretion process. It is made up of a renal corpuscle and renal tubules. The other options are not involved in the kidney's excretion process.
Quick Tip: Nephrons are the building blocks of kidney function, and they play a key role in waste filtration and fluid regulation in the body.

Xylem is a vascular tissue in plants that transports water and dissolved minerals from the roots to other parts of the plant. It also provides structural support to the plant. The other functions, such as the transport of food, are carried out by different plant tissues like phloem.
Quick Tip: Xylem is primarily responsible for water transport, while phloem takes care of food transport in plants.

Autotrophic nutrition is the process by which organisms produce their own food using carbon dioxide, water, and sunlight. Chlorophyll plays a crucial role in capturing the sunlight energy needed for photosynthesis. Therefore, all of these components are essential for autotrophic nutrition.
Quick Tip: Remember, autotrophs (like plants) utilize sunlight, carbon dioxide, and water to produce food.

During cellular respiration, pyruvate is oxidized in the mitochondria in the presence of oxygen. In the mitochondria, pyruvate is converted into acetyl-CoA, which then enters the citric acid cycle.
Quick Tip: Pyruvate is processed in the mitochondria when oxygen is available, making it a key location for energy production.

Mendel's experiments were mainly aimed at understanding how traits are inherited. He used pea plants to investigate the transmission of traits across generations, which led to the development of the laws of inheritance.
Quick Tip: Mendel’s work laid the foundation for modern genetics by demonstrating how traits are inherited.

Chlorofluorocarbons (CFCs) are the main contributors to the depletion of the ozone layer. These compounds release chlorine atoms in the stratosphere, which interact with ozone molecules, causing them to break down.
Quick Tip: CFCs are a major environmental concern as they directly impact the ozone layer, which protects us from harmful ultraviolet radiation.

A food chain typically starts with producers (like grass), followed by primary consumers (like herbivores such as goats), and then secondary consumers (like humans who consume the goat). Therefore, the correct food chain is Grass, goat, and human.
Quick Tip: In a food chain, producers are consumed by primary consumers, and primary consumers are consumed by secondary consumers.

Refraction is the phenomenon where light bends as it moves from one medium to another. This occurs because light travels at different speeds in different media. When light enters a medium with a different refractive index, it bends at the boundary. The degree of bending depends on the angle of incidence and the refractive indices of the two media. The refractive index \(n\) is calculated using the formula: \[ n = \frac{speed of light in vacuum}{speed of light in the medium}. \]
Quick Tip: When light moves from a denser medium to a rarer one, it bends away from the normal.

Hypermetropia, or farsightedness, is a condition in which distant objects are seen clearly, while close objects appear blurred. This happens when the eyeball is too short or the lens has insufficient curvature. As a result, the focal point of the eye is located beyond the retina. Convex lenses are used to correct hypermetropia, as they help bring the focal point closer to the retina, enabling clear vision for nearby objects.

Quick Tip: Convex lenses help converge light rays to focus the image on the retina for hypermetropia correction.

The focal length \(f\) of a convex mirror is given by the formula: \[ f = \frac{R}{2} \]
where \(R\) denotes the radius of curvature of the mirror.

Convex mirrors have several practical uses:
1. They are commonly used as rearview mirrors in vehicles because they provide a wider field of vision.
2. Additionally, they are utilized in security systems for monitoring large areas.
Quick Tip: Convex mirrors have a wide field of view and form virtual, diminished images.

Using the lens formula: \[ \frac{1}{f} = \frac{1}{v} - \frac{1}{u} \]
where:
- \( f = 20 \, cm \) (focal length),
- \( u = -30 \, cm \) (object distance; negative as per sign convention),
- \( v \) is the image distance (unknown).


Substitute the known values into the lens formula: \[ \frac{1}{20} = \frac{1}{v} - \frac{1}{-30} \] \[ \frac{1}{v} = \frac{1}{20} + \frac{1}{30} \]
To simplify: \[ \frac{1}{v} = \frac{3 + 2}{60} = \frac{5}{60} \] \[ v = 12 \, cm \]

The positive value of \( v \) indicates that the image is formed on the opposite side of the object, which means it is a real and inverted image.
Quick Tip: For convex lenses, when the object is beyond the focal point, the image formed is real, inverted, and on the opposite side of the object.

The force on a current-carrying conductor in a magnetic field depends on the following factors:

The strength of the magnetic field (B),
The current \(I\) flowing through the conductor,
The length of the conductor \(L\) within the magnetic field,
The angle between the direction of the magnetic field and the current (denoted as \(\theta\)).

The force can be calculated using the formula: \[ F = BIL \sin \theta \] Quick Tip: The force is maximum when the current is perpendicular to the magnetic field.

The differences between a magnet and a current-carrying solenoid are as follows:

Quick Tip: A current-carrying solenoid creates a magnetic field that behaves like a bar magnet.

The right-hand thumb rule states that if the right-hand thumb is held in the direction of the current in a straight conductor, the curl of the fingers shows the direction of the magnetic field around the conductor.


For a straight current-carrying wire:

- The current flows along the wire in a certain direction.

- If you hold the wire with your right hand such that the thumb points in the direction of the current, the curl of your fingers indicates the direction of the magnetic field lines around the wire.

- These magnetic field lines form concentric circles around the wire, with the direction determined by the curl of your fingers.
Quick Tip: Use your right hand: Thumb shows current, fingers show the direction of the magnetic field.

The circuit involves resistors in series and parallel. First, the two 4 \(\Omega\) resistors are in parallel. The total resistance of this parallel combination is: \[ \frac{1}{R_{parallel}} = \frac{1}{4} + \frac{1}{4} = \frac{2}{4} = \frac{1}{2} \] \[ R_{parallel} = 2 \, \Omega \]
Now, this 2 \(\Omega\) combination is in series with the 5 \(\Omega\) resistor, so the total resistance of this combination is: \[ R_{total1} = 2 + 5 = 7 \, \Omega \]
Next, this 7 \(\Omega\) is in parallel with the 10 \(\Omega\) resistor: \[ \frac{1}{R_{total}} = \frac{1}{7} + \frac{1}{10} \] \[ \frac{1}{R_{total}} = \frac{10 + 7}{70} = \frac{17}{70} \] \[ R_{total} = \frac{70}{17} \approx 4.12 \, \Omega \]
So the equivalent resistance between A and B is approximately \(4.12 \, \Omega\).


Now, using Ohm's law, the total current in the circuit is: \[ I = \frac{V}{R_{total}} = \frac{6}{4.12} \approx 1.46 \, A \]
The potential difference across the 5 \(\Omega\) resistor can be found using: \[ V = I \times 5 = 1.46 \times 5 = 7.3 \, V \] Quick Tip: When calculating the equivalent resistance of resistors in parallel, use the formula \(\frac{1}{R_{total}} = \sum \frac{1}{R_i}\). In series, simply add the resistances.

A fuse is an essential safety device used in electrical circuits. It prevents damage to the electrical appliances and wiring by melting and breaking the circuit when the current exceeds a safe value, thereby protecting the circuit from overheating and potential fires. The rating of the fuse is based on the maximum current that the circuit is expected to handle.

The current in the circuit can be calculated using the formula: \[ I = \frac{P}{V} = \frac{2200 \, W}{220 \, V} = 10 \, A \]
Therefore, the fuse should have a rating of at least 10 A.

The commercial unit of electrical energy is the kWh (kilowatt-hour), which is the energy consumed by a 1 kW load in 1 hour. 1 kWh is equivalent to 1000 watts used for 1 hour.
Quick Tip: When selecting a fuse, ensure the fuse rating is slightly higher than the normal operating current of the circuit to prevent unnecessary blows.

In a domestic electrical circuit, three types of wires are used:

Live wire: The wire that carries current to the load. It is usually coloured red or brown.
Neutral wire: The wire that completes the circuit by carrying current away from the load. It is coloured blue.
Earth wire: This wire provides safety by carrying current directly to the ground in case of a fault. It is coloured green or yellow-green.

Quick Tip: Always check the colour coding of wires before handling them to ensure safety and proper connection in circuits.

The longest carbon chain in this compound has 3 carbon atoms, so the base name is "propane". The bromine atom is attached to the first carbon, so the name is 1-Bromopropane.
Quick Tip: In IUPAC naming, always number the carbon chain from the end nearest to the functional group (in this case, bromine).

An example of a combination reaction is:
[ A + B  AB ]
Quick Tip: A combination reaction occurs when two or more reactants combine to form a single product.

The balanced chemical equation for the given reaction is:
\[ BaCl_2 (aq) + Al_2(SO_4)_3 (aq) \rightarrow BaSO_4 (s) + 2AlCl_3 (aq) \]
Quick Tip: In a combination reaction, the products are simpler compounds formed from the combination of reactants.

(i) The electronic configuration of Sodium (Na) is:
\[ Na: 1s^2 \, 2s^2 \, 2p^6 \, 3s^1 \]


(ii) The electronic configuration of Chlorine (Cl) is:
\[ Cl: 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^5 \]
Quick Tip: To write the electronic configuration, follow the Aufbau principle and fill orbitals in order of increasing energy.

(a) Acid Rain: Acid rain refers to rainwater that becomes acidic due to pollutants like sulfur dioxide and nitrogen oxides, which react with water vapor in the atmosphere. This can lead to environmental damage, including harm to plant life, aquatic ecosystems, and structures.


(b) Ductility and Malleability: Ductility is the property of a material that allows it to be drawn into thin wires, while malleability is the ability of a material to be hammered into thin sheets. Both of these properties are characteristic of metals.


(c) Micelle: A micelle is a cluster of surfactant molecules in water, with the hydrophobic tails facing inward and the hydrophilic heads pointing outward. Micelles help dissolve hydrophobic substances, such as oils and fats, in water.

Quick Tip: When studying properties like ductility and malleability, focus on their applications in material science and their relation to the atomic structure of metals.

Corrosion is the process by which metals deteriorate as a result of chemical reactions with their environment, typically involving oxygen or moisture. For example, iron reacts with water and oxygen to produce rust (iron oxide).

Two common methods to prevent corrosion are:
1. Galvanization: This method involves applying a protective layer of zinc to the metal to safeguard it from environmental factors.

2. Use of corrosion-resistant materials: Choosing alloys such as stainless steel, which are less prone to corrosion. Quick Tip: Corrosion can be minimized by using protective coatings or choosing corrosion-resistant materials.

(i) Exothermic reactions: These reactions release energy in the form of heat or light. The energy needed to break bonds is less than the energy released when new bonds are formed. An example is the combustion of wood, where energy is emitted as heat and light.


(ii) Endothermic reactions: These reactions absorb energy from their surroundings. The energy required to break bonds exceeds the energy released when new bonds are formed. An example is photosynthesis, where plants capture sunlight to convert carbon dioxide and water into glucose.

Quick Tip: Exothermic reactions release energy, while endothermic reactions absorb energy.

The structure of a nerve cell (neuron) includes the following components:
1. Cell body (Soma): Contains the nucleus and other organelles.
2. Dendrites: Branch-like structures that receive signals from neighboring neurons.
3. Axon: A long extension that carries electrical impulses away from the cell body.
4. Axon terminals: The branching ends of the axon that transmit signals to the subsequent neuron.

Functions: The nerve cell transmits electrical signals, facilitating communication with other neurons, muscles, or glands within the body.
Quick Tip: The axon is the main conducting part of a neuron, while dendrites receive stimuli.

Thyroxine, produced by the thyroid gland, is essential for regulating metabolism. It boosts the rate of energy production in cells, aiding in the maintenance of body temperature and supporting normal growth and development.


% Option (ii)
(ii) Budding


% Solution (ii)
Solution:

Budding is a type of asexual reproduction where a new organism grows from a bud on the parent organism. The new organism may eventually separate from the parent, becoming an independent individual. This method is commonly observed in yeast and hydra.
Quick Tip: Thyroxine is essential for controlling the body's metabolism, while budding is a type of asexual reproduction.

In flowering plants, sexual reproduction involves the fusion of male and female gametes (sperm and ovule). The process starts with pollination, where pollen from the male reproductive part (anther) reaches the female reproductive part (stigma). The sperm cells then move through the style to fertilize the ovule in the ovary. Following fertilization, the ovule becomes a seed, and the ovary transforms into the fruit.
Quick Tip: Sexual reproduction in plants ensures genetic diversity through the fusion of male and female gametes.

In humans, oxygen is carried by red blood cells in the form of oxyhemoglobin. Oxygen binds to hemoglobin in the lungs and is then transported to tissues. Carbon dioxide is returned to the lungs in three forms: dissolved in plasma, bound to hemoglobin, and as bicarbonate ions (HCO\(_3^-\)) in the plasma.
Quick Tip: The majority of carbon dioxide is carried as bicarbonate ions in the blood, while oxygen binds to hemoglobin.

The human heart is a four-chambered organ, consisting of two atria and two ventricles. The right atrium receives deoxygenated blood from the body and pumps it into the right ventricle, which then sends it to the lungs for oxygenation. The left atrium receives oxygenated blood from the lungs and pumps it into the left ventricle, which distributes it throughout the body. The heart also contains valves that control the flow of blood between the chambers and prevent backflow.

Quick Tip: The left ventricle pumps oxygenated blood to the entire body, while the right ventricle pumps deoxygenated blood to the lungs.