Welcome back, students! The crucial UP Board Exam 2026 is quickly approaching, and having the correct study materials is essential for success. We know that finding reliable, English-medium solutions for specific question papers can be challenging. Many of you search for Class 10 Science Important Questions 2026 UP Board, but a fully solved paper is the best way to prepare.
To help you score top marks, we have prepared the complete UP Board Class 10 Science Solved Paper 2026 Set 824 EP. Whether you are from the Hindi medium or English medium (feel free to use our site's translate feature), these solutions are designed to clarify your concepts. This comprehensive Science paper set 824 (EP) solution includes everything from detailed Physics ray diagrams and Chemistry chemical equations to in-depth Biology explanations and all MCQs.
Practicing with this fully solved UP Board 10th Science Paper Set 824 (EP) will solidify your understanding and boost your confidence for the exams. Let us dive into the solutions and strengthen your preparation!
PART - A: Multiple Choice Questions (MCQs)
Sub-Section - (a) | Physics
👁️ View Answer
Ans: (A) 40 cm; concave.Explanation: Power of a lens, \(P = \frac{100}{f(\text{in cm})}\).
Given \(P = -2.5 \text{ D}\).
Therefore, \(f = \frac{100}{-2.5} = -40 \text{ cm}\).
A negative focal length indicates that the lens is concave.
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Ans: (D) \(\sqrt{\frac{P}{R}}\).Explanation: The formula relating power (\(P\)), current (\(I\)), and resistance (\(R\)) is \(P = I^2R\).
Rearranging for current gives \(I^2 = \frac{P}{R}\), so \(I = \sqrt{\frac{P}{R}}\).
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Ans: (B) \(v_2 / v_1\).Explanation: The refractive index of medium 1 with respect to medium 2 (\(_{2}n_{1}\)) is defined as the ratio of the speed of light in medium 2 to the speed of light in medium 1. Therefore, \(_{2}n_{1} = \frac{v_2}{v_1}\).
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Ans: (C) Magnetic field lines intersect each other.Explanation: Magnetic field lines never intersect. If they did, it would mean that at the point of intersection, a compass needle would point in two different directions, which is impossible.
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Ans: (A) Convex mirror.Explanation: A convex mirror bulges outwards. This shape allows it to gather light from a wider angle, providing a larger, wider field of view compared to plane or concave mirrors. This is why they are used as rear-view mirrors in vehicles.
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Ans: (B) \(\frac{R_1}{R_2} = \frac{9}{2}\).Explanation:
In series, \(R_1 = R + 2R = 3R\).
In parallel, \(\frac{1}{R_2} = \frac{1}{R} + \frac{1}{2R} = \frac{3}{2R}\), so \(R_2 = \frac{2R}{3}\).
The ratio \(\frac{R_1}{R_2} = \frac{3R}{(2R/3)} = \frac{9}{2}\).
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Ans: (A) increases \(n\) times.Explanation: The magnetic field produced by a circular coil at its center is directly proportional to the number of turns (\(n\)). This is because the magnetic field from each turn adds up in the same direction.
Sub-Section - (b) | Chemistry
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Ans: (A) Ethanol.Explanation: The compound contains two carbon atoms (prefix 'eth-') and an alcohol functional group (\(\text{-OH}\)), which gives the suffix '-anol'. Therefore, its IUPAC name is Ethanol.
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Ans: (C) \(\text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O} + \text{Heat and Light}\).Explanation: Combustion is a chemical process where a substance reacts rapidly with oxygen and gives off heat and light. The burning of methane (\(\text{CH}_4\)) in oxygen perfectly describes this.
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Ans: (A) A new orbit is added on going down in a group.Explanation: As you move down a group in the periodic table, a new electron shell (orbit) is added to the atoms of each successive element. This increases the distance between the nucleus and the outermost electrons, making the atom larger.
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Ans: (D) \(\text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O}\).Explanation: Plaster of Paris is calcium sulphate hemihydrate. It is formed by heating gypsum to 373 K, causing it to lose water molecules. Its formula is \(\text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O}\).
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Ans: (B) 7.Explanation: Pure water is neutral; it is neither acidic nor basic. On the pH scale, which ranges from 0 to 14, a value of exactly 7 represents a neutral substance.
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Ans: (B) \(\text{-CHO}\).Explanation: The distinguishing feature of an aldehyde is the presence of the formyl group, which is written as \(\text{-CHO}\). It consists of a carbon double-bonded to an oxygen and single-bonded to a hydrogen.
Sub-Section - (c) | Biology
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Ans: (D) Green plants.Explanation: In any ecosystem, organisms that can synthesize their own food using sunlight (through photosynthesis) are called producers. Green plants fall into this category.
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Ans: (A) All long plants.Explanation: According to Mendel's Law of Dominance, when homozygous dominant (TT) and homozygous recessive (tt) parents are crossed, all offspring in the first generation (\(F_1\)) will be heterozygous (Tt). Since 'T' is dominant for tallness, all plants will appear tall (long).
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Ans: (C) Water and Carbon dioxide.Explanation: Photosynthesis is the process by which green plants use sunlight to synthesize nutrients from carbon dioxide and water. Oxygen is released as a byproduct, not used as a reactant.
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Ans: (D) Stigma.Explanation: A unisexual male flower contains only the male reproductive parts (stamens). It lacks the female reproductive parts, which consist of the stigma, style, and ovary (collectively known as the carpel or pistil).
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Ans: (B) pancreas.Explanation: Insulin is a crucial hormone that regulates blood sugar levels. It is produced and secreted by specialized cells (beta cells) located in the Islets of Langerhans within the pancreas.
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Ans: (A) Charles Darwin.Explanation: Charles Darwin formulated the theory of evolution by natural selection. This theory explains how organisms change over time as a result of changes in heritable physical or behavioral traits.
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Ans: (D) All of the above.Explanation: Fossil fuels like coal and petroleum are complex mixtures containing mainly carbon, along with traces of nitrogen and sulphur. When burned, they release carbon dioxide, as well as oxides of nitrogen and sulphur, which contribute to air pollution and acid rain.
PART - B: Descriptive Questions (Solutions)
Sub-Section - a | Physics Long Answers
Solution:
To obtain a virtual, erect, and magnified image from a concave mirror, the object must be placed very close to it, specifically between the pole (\(P\)) and the principal focus (\(F\)) of the mirror.
In the ray diagram:
- A ray parallel to the principal axis passes through the focus (\(F\)) after reflection.
- A ray directed towards the center of curvature (\(C\)) reflects back along the same path.
- These reflected rays diverge in front of the mirror but appear to meet at a point behind the mirror when extended backward, forming a virtual and magnified image (\(A'B'\)).
Use: Because it can form an enlarged, upright image when held close, a concave mirror is widely used as a shaving mirror or a dentist's mirror to see a larger image of the face or teeth, respectively.
Solution:
The phenomenon of splitting of white light into its component colors when it passes through a transparent medium like a glass prism is called dispersion of light.
White light from the sun is a mixture of seven colors: Violet, Indigo, Blue, Green, Yellow, Orange, and Red (remembered by the acronym VIBGYOR). When a narrow beam of white light enters a triangular glass prism, it undergoes refraction (bending) at the first surface.
Each color has a different wavelength and travels at a different speed within the glass. Therefore, each color bends by a different angle relative to the incident ray.
- Red light has the longest wavelength and travels fastest in glass, so it bends the least.
- Violet light has the shortest wavelength and travels slowest in glass, so it bends the most.
This differential bending separates the white light into a distinct band of seven colors on a screen, known as a spectrum.
[Image of dispersion of white light through a prism]Solution:
Ohm's Law: It states that the electric current (\(I\)) flowing through a metallic conductor is directly proportional to the potential difference (\(V\)) applied across its ends, provided physical conditions (like temperature) remain constant. Mathematically: \(V \propto I\) or \(V = IR\), where \(R\) is a constant called resistance.
Verification of Ohm's Law:
To verify Ohm's law, we set up a circuit consisting of a nichrome wire (resistor \(R\)), an ammeter (to measure current), a voltmeter (to measure potential difference), a variable source of voltage (like a battery eliminator or multiple cells), a rheostat, and a plug key.
- Connections: The ammeter is connected in series with the resistor, while the voltmeter is connected in parallel across the resistor.
- Procedure: Close the key to complete the circuit. Adjust the rheostat to allow a small current to flow. Record the readings of the ammeter (\(I\)) and the voltmeter (\(V\)).
- Change the position of the rheostat slider to vary the current in the circuit. Take several pairs of readings for \(V\) and \(I\).
- Observation: For every set of readings, calculate the ratio \(\frac{V}{I}\). You will observe that this ratio remains approximately constant (\(\frac{V}{I} = R\)).
- Conclusion: If you plot a graph of potential difference (\(V\)) on the Y-axis versus current (\(I\)) on the X-axis, it will be a straight line passing through the origin. This straight-line graph experimentally verifies Ohm's law, proving that \(V\) is directly proportional to \(I\).
Solution:
Electromagnetic Induction: The phenomenon in which an electric current is generated in a closed circuit (like a coil) due to a changing magnetic field linked with it is called electromagnetic induction. The current generated is called induced current.
Faraday's Experiment:
Michael Faraday conducted famous experiments to demonstrate this phenomenon. The setup involves a coil of many turns of insulated copper wire connected to a sensitive galvanometer (which detects tiny currents). A strong bar magnet is used.
- Magnet at Rest: When the magnet is held stationary near or inside the coil, the galvanometer shows no deflection, indicating zero current.
- Magnet Moved Inward: When the North pole of the magnet is pushed quickly into the coil, the galvanometer pointer deflects momentarily in one direction. This shows that a current is induced in the coil as the magnetic field linked with it increases.
- Magnet Moved Outward: When the magnet is pulled quickly out of the coil, the galvanometer pointer deflects again, but in the opposite direction. The induced current reverses direction as the magnetic field decreases.
- Coil Moved, Magnet Stationary: The same effects are observed if the magnet is kept stationary and the coil is moved towards or away from it.
Conclusion from Experiment: Faraday concluded that relative motion between a coil and a magnet induces an electromotive force (EMF) and a corresponding current in the coil. It is the change in magnetic field lines passing through the coil that is responsible for electromagnetic induction.
Sub-Section - b | Chemistry Long Answers
(i) Importance of pH in daily life
(ii) Exothermic chemical reactions
Solution:
(i) Importance of pH in daily life:
The pH scale measures how acidic or basic a substance is. It is crucial in many aspects of daily life:
- Digestive System: Our stomach produces dilute hydrochloric acid (\(\text{HCl}\)), which lowers the pH to around 1.5 - 3.5. This highly acidic environment is necessary to activate enzymes (like pepsin) for digesting proteins and to kill harmful bacteria in food. Indigestion causes excess acid, treated with antacids (mild bases like milk of magnesia) to neutralize it.
- Tooth Decay: Tooth enamel is made of calcium hydroxyapatite. When we eat sugary foods, bacteria in the mouth produce acids that lower the pH. If the pH in the mouth falls below 5.5, the acid starts corroding the enamel, leading to tooth decay. Using basic toothpastes helps neutralize this acid.
(ii) Exothermic chemical reactions:
Reactions in which heat is released along with the formation of products are called exothermic reactions. The total energy of the products is less than the total energy of the reactants.
Examples:
- Respiration: The process of respiration in our bodies is exothermic. Glucose combines with oxygen in cells, releasing energy that our body uses to function.
\(\text{C}_6\text{H}_{12}\text{O}_6(\text{aq}) + 6\text{O}_2(\text{g}) \rightarrow 6\text{CO}_2(\text{g}) + 6\text{H}_2\text{O}(\text{l}) + \text{Energy}\) - Burning of Natural Gas: Combustion reactions are highly exothermic. When methane burns, it releases significant heat.
\(\text{CH}_4(\text{g}) + 2\text{O}_2(\text{g}) \rightarrow \text{CO}_2(\text{g}) + 2\text{H}_2\text{O}(\text{g}) + \text{Heat}\)
(b) How will you obtain the following : (Write chemical equations)
(i) Washing Soda from Baking Soda
(ii) Plaster of Paris from Gypsum
Solution:
(a) Chemical properties of Ethanoic Acid (\(\text{CH}_3\text{COOH}\)):
1. Reaction with a base (Neutralization): Ethanoic acid reacts with a base like sodium hydroxide (\(\text{NaOH}\)) to form a salt (sodium ethanoate) and water.
\(\text{CH}_3\text{COOH} + \text{NaOH} \rightarrow \text{CH}_3\text{COONa} + \text{H}_2\text{O}\)
2. Reaction with carbonates/bicarbonates: It reacts with sodium carbonate or sodium bicarbonate to produce brisk effervescence due to the evolution of carbon dioxide gas.
\(2\text{CH}_3\text{COOH} + \text{Na}_2\text{CO}_3 \rightarrow 2\text{CH}_3\text{COONa} + \text{H}_2\text{O} + \text{CO}_2\uparrow\)
(b) Obtaining compounds:
(i) Washing Soda from Baking Soda: When baking soda (sodium hydrogencarbonate) is heated strongly, it decomposes to form sodium carbonate. This sodium carbonate is then dissolved in water and recrystallized to obtain washing soda (\(\text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O}\)).
Heating: \(2\text{NaHCO}_3 \xrightarrow{\text{Heat}} \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2\uparrow\)
Recrystallization: \(\text{Na}_2\text{CO}_3 + 10\text{H}_2\text{O} \rightarrow \text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O}\)
(ii) Plaster of Paris from Gypsum: Plaster of Paris is obtained by heating Gypsum (\(\text{CaSO}_4 \cdot 2\text{H}_2\text{O}\)) carefully in a kiln to a temperature of 373 K (\(100^\circ\text{C}\)). It loses partially its water of crystallization to form calcium sulphate hemihydrate.
\(\text{CaSO}_4 \cdot 2\text{H}_2\text{O} \xrightarrow{373\text{ K}} \text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O} + 1\frac{1}{2}\text{H}_2\text{O}\)
(i) Cleansing action of soap
(ii) Calcination and Roasting
(iii) Activity series of metals
Solution:
(i) Cleansing action of soap:
A soap molecule has two parts: a long hydrocarbon tail that is hydrophobic (water-repelling but dirt/oil-attracting) and an ionic head that is hydrophilic (water-attracting). Most dirt is oily in nature. When soap is added to dirty water, the hydrophobic tails attach themselves to the oily dirt particle, while the hydrophilic heads point outward towards the water. This forms spherical structures called micelles. The micelles trap the dirt in the center. Because the outer surface of micelles is negatively charged, they repel each other and stay suspended in water as an emulsion. When rinsed, the water washes away the micelles along with the trapped dirt, cleaning the cloth.
(ii) Calcination and Roasting:
Both are processes used in metallurgy to convert ores into their respective metal oxides, but they are used for different types of ores.
- Calcination: It is the process of heating a carbonate ore strongly in the absence or limited supply of air. It is used to drive off carbon dioxide and moisture.
Example (Zinc carbonate): \(\text{ZnCO}_3(s) \xrightarrow{\text{Heat}} \text{ZnO}(s) + \text{CO}_2(g)\) - Roasting: It is the process of heating a sulphide ore strongly in the presence of excess air. It is used to convert sulphides into oxides and remove sulphur as sulphur dioxide gas.
Example (Zinc blende): \(2\text{ZnS}(s) + 3\text{O}_2(g) \xrightarrow{\text{Heat}} 2\text{ZnO}(s) + 2\text{SO}_2(g)\)
(iii) Activity series of metals:
The activity series (or reactivity series) of metals is a list in which metals are arranged in decreasing order of their chemical reactivity. Highly reactive metals like Potassium (K) and Sodium (Na) are placed at the top, moderately reactive metals like Zinc (Zn) and Iron (Fe) are in the middle, and least reactive (noble) metals like Gold (Au) and Platinum (Pt) are at the bottom. This series helps predict whether a metal can displace another metal from its salt solution; a more reactive metal can displace a less reactive one.
Sub-Section - c | Biology Long Answers
(ii) In which organ of body 'Copper-T' is placed ?
(iii) On which plant did Mendel perform his experiment ?
(iv) Give examples of homologous organs.
Solution:
(i) Function of Xylem: The main function of the xylem tissue in plants is the unidirectional transport of water and dissolved minerals from the roots up to the stem and leaves.
(ii) Placement of Copper-T: The Copper-T (an intrauterine device or IUD) is placed safely inside the female's uterus by a medical professional to prevent pregnancy.
(iii) Mendel's plant: Gregor Mendel performed his groundbreaking genetics experiments on the Garden Pea plant (\(\text{Pisum sativum}\)).
(iv) Examples of homologous organs: Homologous organs have a similar fundamental structure and origin but may perform different functions. Examples include the forelimbs of a human (used for grasping), a bird (used for flying), a whale (used for swimming), and a frog (used for propping).
Solution:
Double circulation is a complex circulatory system found in humans and other mammals where blood passes through the heart twice to complete one full circuit of the body. It consists of two separate pathways: pulmonary circulation and systemic circulation. This system ensures efficient separation of oxygen-rich and oxygen-poor blood.
1. Pulmonary Circulation:
This path connects the heart and the lungs. Deoxygenated blood from the body enters the right atrium and is pumped into the right ventricle. The right ventricle contracts, pumping this oxygen-poor blood through the pulmonary artery to the lungs. In the lungs, carbon dioxide is released, and oxygen is absorbed. The newly oxygenated blood travels via the pulmonary veins back to the left atrium of the heart, completing the pulmonary circuit.
2. Systemic Circulation:
This path connects the heart with the rest of the body. Oxygenated blood from the left atrium enters the left ventricle. The thick-walled left ventricle contracts powerfully to pump this oxygen-rich blood through the aorta to all organs and tissues of the body (except the lungs). The tissues use the oxygen and release carbon dioxide into the blood. This deoxygenated blood is collected by veins (venae cavae) and returned to the right atrium of the heart, completing the systemic circuit.
Importance: The right side of the heart handles only deoxygenated blood, while the left handles only oxygenated blood. This strict separation prevents mixing, ensuring a highly efficient supply of oxygen to the body's cells, which is necessary to maintain high energy levels and a constant body temperature in mammals.
(i) Conservation of natural resources
(ii) Regeneration
Solution:
(i) Conservation of natural resources:
Conservation refers to the careful management, sustainable use, and protection of Earth's natural resources—such as water, soil, forests, wildlife, and fossil fuels—to prevent their depletion. As the human population grows, the demand for these resources increases, leading to overexploitation and environmental degradation. Conservation is vital for maintaining ecological balance and ensuring that future generations have access to necessary resources. It involves practices like reducing waste (Reduce, Reuse, Recycle), using renewable energy sources (solar, wind), planting trees, preventing pollution, and protecting biodiversity. Sustainable development is the ultimate goal of conservation.
(ii) Regeneration:
Regeneration is a specialized form of asexual reproduction and tissue repair found in certain organisms. It is the ability of an organism to regrow or restore lost, damaged, or severed body parts. In some simple animals, if the body is cut into several pieces, each piece can grow back the missing parts to become a complete new organism. For example, if a Planaria (a flatworm) or a Hydra is cut into pieces, specialized cells proliferate and differentiate to form the missing tissues, resulting in multiple complete individuals. Regeneration is carried out by specialized stem cells. However, in higher animals like humans, regeneration is highly restricted (e.g., healing of wounds, limited liver regeneration).
Solution:
Structure of a Nephron:
The nephron is the basic structural and functional unit of the kidney, responsible for filtering blood and forming urine. Each kidney contains millions of nephrons. A nephron consists of two main parts: the Malpighian corpuscle (filtering unit) and the renal tubule.
- Bowman's Capsule: It is a cup-shaped structure at the beginning of the nephron.
- Glomerulus: Inside the Bowman's capsule is a dense network of blood capillaries called the glomerulus. Together, the Bowman's capsule and glomerulus form the Malpighian corpuscle.
- Renal Tubule: The Bowman's capsule extends into a long, coiled tubular structure which is divided into three parts:
- Proximal Convoluted Tubule (PCT): Highly coiled region near the capsule.
- Loop of Henle: A U-shaped segment dipping into the renal medulla.
- Distal Convoluted Tubule (DCT): Coiled region that empties into a collecting duct.
Functioning of a Nephron (Urine Formation):
The formation of urine involves three major steps:
- Ultrafiltration: Blood enters the glomerulus under high pressure. This pressure forces water, urea, glucose, amino acids, and salts out of the blood capillaries and into the Bowman's capsule. This fluid is called the glomerular filtrate. Large molecules like blood cells and proteins remain in the blood.
- Selective Reabsorption: As the filtrate flows through the PCT, Loop of Henle, and DCT, useful substances that the body needs are selectively reabsorbed back into the surrounding blood capillaries. This includes almost all glucose and amino acids, along with necessary amounts of water and salts.
- Tubular Secretion: Certain waste products, like extra potassium ions, hydrogen ions, and some drugs, are actively secreted from the blood capillaries into the renal tubule to be eliminated.
The final fluid that reaches the collecting duct after these processes is urine, which contains water, urea, uric acid, and excess salts.
Conclusion
Dear students, rigorously practicing these solutions from the UP Board Class 10 Science Solved Paper 2026 Set 824 EP will undeniably enhance your exam readiness. Focus on the descriptive answers and practice drawing the ray diagrams and circuits. We wish you the very best of luck!
Frequently Asked Questions (FAQs)
Q1. Are these the exact questions that will appear in the 2026 UP Board Exam?
Ans: These questions are meticulously modeled after the UP Board pattern and previous years' trends. While exact repetition is not guaranteed, mastering these concepts covers the most probable exam topics.
Q2. Does writing answers in English medium affect scoring in the UP Board?
Ans: Absolutely not. The UP Board evaluates answers based on accuracy and understanding of scientific concepts, regardless of whether the medium is Hindi or English. Clear and correct answers earn full marks.
