--- title: "CBSE Class 10 Science Question Paper 2022 (Set 31/1/1) with Solutions" url: https://www.swavid.com/cbse/class-10/science/previous-year-papers/2022-31-1-1 dateModified: 2026-10-07T15:27:26+00:00 --- # CBSE Class 10 Science Question Paper 2022 (Set 31/1/1) with Solutions Code 31/1/1 · 40 marks · 120 minutes Solved CBSE Class 10 Science board paper from 2022, set 31/1/1. Every question has step-by-step working written to the CBSE marking scheme, with the marks for each answer. Official question paper: https://www.cbse.gov.in/cbsenew/question-paper/2022/X/Scince.zip. Solutions written by SwaVid. Free PDF (15 pages): https://www.swavid.com/api/seo/pdf/papers/cbse/science/swavid-cbse-class-10-science-question-paper-2022-31-1-1-a79d2bf28f.pdf ## SECTION A Questions No. 1 to 7 are short answer type questions. Each question carries 2 marks. ### Question 1 *2 marks · Short answer · Carbon and its Compounds* (a) Write the molecular formula of the following carbon compounds : (i) Methane (ii) Propane (b) Carbon compounds have low melting and boiling points. Why ? **Part (a)(i)** 1. Methane has one carbon atom, so its molecular formula is $\text{CH}_4$. Answer (a)(i): $\text{CH}_4$ **Part (a)(ii)** 1. Propane has three carbon atoms, so its molecular formula is $\text{C}_3\text{H}_8$. Answer (a)(ii): $\text{C}_3\text{H}_8$ **Part (b)** 1. Carbon compounds are generally covalent compounds formed by the sharing of electrons. 2. They have weak forces of attraction between their molecules, requiring very little energy to break. Answer (b): Weak intermolecular forces result in low melting and boiling points. **Answer:** Methane is $\text{CH}_4$, propane is $\text{C}_3\text{H}_8$, and carbon compounds have low melting and boiling points due to weak intermolecular forces. > Common mistake: Confusing molecular formulas of alkanes or attributing ionic bonding to carbon compounds. ### Question 2 *2 marks · Short answer · Carbon and its Compounds* The electrons in the atoms of two elements X and Y are distributed in three shells having 1 and 7 electrons respectively in their outermost shells. (a) Write the group numbers of these elements in the Modern Periodic Table. (b) Write the molecular formula of the compound formed when X and Y combine with each other. (c) Which of the two is electropositive ? **Part (a)** 1. Element X has 1 valence electron and 3 shells, placing it in Period 3 and Group 1. 2. Element Y has 7 valence electrons and 3 shells, placing it in Period 3 and Group 17. Answer (a): Group 1 for X and Group 17 for Y **Part (b)** 1. Element X has a valency of 1 and element Y has a valency of 1. 2. Combining them gives the molecular formula XY. Answer (b): XY **Part (c)** 1. Element X is a metal with 1 valence electron which it tends to lose easily to form a positive ion. Answer (c): Element X **Answer:** Element X is in Group 1, element Y is in Group 17, the formula is XY, and X is electropositive. > Common mistake: Writing group numbers without considering the total number of valence electrons. ### Question 3 *2 marks · Short answer · How do Organisms Reproduce?* (a) Which of the following flowers will have higher possibility of self-pollination ? Mustard, Papaya, Watermelon, Hibiscus (b) List the two reproductive parts of a bisexual flower. **Part (a)** 1. Hibiscus is a bisexual flower containing both male and reproductive organs, giving a high possibility of self-pollination. Answer (a): Hibiscus **Part (b)** 1. The male reproductive part is the stamen (anther and filament). 2. The female reproductive part is the pistil or carpel (stigma, style, and ovary). Answer (b): Stamen and pistil **Answer:** Hibiscus has a higher possibility of self-pollination, and the two reproductive parts of a bisexual flower are stamen and pistil. > Common mistake: Naming unisexual flowers like papaya or watermelon for self-pollination. ### Question 4 *2 marks · Short answer · How do Organisms Reproduce?* Which one of the two multicellular organisms — Spirogyra and Planaria reproduces by regeneration and why ? Give an example of any other organism which can also reproduce by the same process. **Solution** 1. Planaria reproduces by regeneration because its body can be cut into pieces and each piece grows into a complete organism through specialized cells. 2. These specialized cells proliferate and make large numbers of cells, undergoing differentiation to form various tissues and organs. 3. An example of another organism that reproduces by regeneration is Hydra. **Answer:** Planaria reproduces by regeneration using specialized cells that proliferate and differentiate; Hydra is another example. > Common mistake: Confusing fragmentation in Spirogyra with true regeneration in Planaria. ### Question 5 *2 marks · Short answer · Heredity* (a) What is variation ? List two main reasons that may lead to variation in a population. **Solution** 1. Variation refers to the differences in characters or traits among individuals of the same species. 2. The two main reasons that lead to variation are inaccuracies during DNA copying and sexual reproduction through the combination of genes from two parents. **Answer:** Variation is the occurrence of differences among individuals, caused by DNA copying errors and sexual reproduction. > Common mistake: Omitting DNA copying errors as a source of variation in asexual organisms. ### Question 5 (OR) *2 marks · Short answer · Heredity* (b) (i) In a cross between violet flowered plants and white flowered plants, state the characteristics of the plants obtained in the $F_1$ progeny. (ii) If the plants of $F_1$ progeny are self-pollinated, then what would be observed in the plants of $F_2$ progeny ? (iii) If 100 plants are produced in $F_2$ progeny, then how many plants will show the recessive trait ? **Part (i)** 1. All the plants obtained in the $F_1$ progeny will have violet flowers. 2. Violet flower colour is the dominant trait which expresses itself in the $F_1$ generation. Answer (i): All plants obtained in the $F_1$ progeny have violet flowers. **Part (ii)** 1. Self-pollination of $F_1$ plants results in both violet and white flowered plants in the $F_2$ progeny. 2. The observed phenotypic ratio is 3 violet flowered plants to 1 white flowered plant. Answer (ii): Both violet and white flowered plants are observed in the ratio of 3:1. **Part (iii)** 1. The proportion of plants showing the recessive white trait in the $F_2$ progeny is $\frac{1}{4}$. 2. Out of 100 plants, the number of plants showing the recessive trait is $\frac{1}{4} \times 100 = 25$. Answer (iii): 25 plants will show the recessive trait. **Answer:** In $F_1$ progeny all plants have violet flowers, in $F_2$ progeny the phenotypic ratio is 3 violet to 1 white, and 25 plants show the recessive trait out of 100. > Common mistake: Confusing the $F_1$ progeny characteristics with $F_2$ progeny or miscalculating the number of recessive plants as 75 instead of 25. ### Question 6 *2 marks · Short answer · Magnetic Effects of Electric Current* (a) (i) Name and state the rule to determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it. (ii) An alpha particle while passing through a magnetic field gets projected towards north. In which direction will an electron project when it passes through the same magnetic field ? **Part (i)** 1. Name: Fleming's Left-Hand Rule. 2. Statement: Stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or the force acting on the conductor. Answer (i): Fleming's Left-Hand Rule states that the thumb, forefinger and middle finger of the left hand point in the direction of force, magnetic field, and current respectively when mutually perpendicular. **Part (ii)** 1. An alpha particle is a positively charged particle, so its motion towards north constitutes a conventional current towards north. 2. An electron is negatively charged, so its motion in the same magnetic field constitutes a current in the direction opposite to its motion. 3. Since the current due to an electron is opposite to that of an alpha particle, the force acting on the electron will be in the opposite direction to that acting on the alpha particle. 4. Therefore, the electron will project towards the south. Answer (ii): Towards south **Answer:** Fleming's Left-Hand Rule determines the force direction; the electron projects towards the south. > Common mistake: Confusing the direction of conventional current for negatively charged particles like electrons. ### Question 6 (OR) *2 marks · Short answer · Magnetic Effects of Electric Current* (b) (i) What is a solenoid ? (ii) Draw the pattern of magnetic field lines of the magnetic field produced by a solenoid through which a steady current flows. **Part (i)** 1. A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid. Answer (i): A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder. **Part (ii)** 1. Diagram: Draw a cylindrical coil with current indicating arrows, showing magnetic field lines emerging from one end and entering the other, forming continuous closed loops inside and outside the solenoid, with parallel lines inside representing a uniform magnetic field. Answer (ii): Field lines inside the solenoid are parallel straight lines indicating a uniform magnetic field, resembling a bar magnet. **Answer:** A solenoid is a coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder. > Common mistake: Drawing field lines that intersect or do not form continuous closed loops. ### Question 7 *2 marks · Short answer · Our Environment* (a) What is ozone ? How is it formed in the upper layers of the Earth's atmosphere ? How does ozone affect our ecosystem ? **Part (a)** 1. Ozone is a molecule formed by three atoms of oxygen ($O_3$). 2. High energy UV radiations split apart molecular oxygen ($O_2$) into free oxygen ($O$) atoms, which then combine with molecular oxygen to form ozone. 3. Ozone shields the surface of the earth from harmful ultraviolet (UV) radiation from the Sun which can cause skin cancer and damage ecosystems. Answer (a): Ozone ($O_3$) is formed in the upper atmosphere by the action of UV rays on oxygen molecules and protects the ecosystem by absorbing harmful UV radiation. **Answer:** Ozone is a molecule formed by three atoms of oxygen ($O_3$), which shields the surface of the earth from harmful UV radiation. > Common mistake: Confusing oxygen ($O_2$) with ozone ($O_3$) in the formation reaction. ### Question 7 (OR) *2 marks · Short answer · Our Environment* (b) (i) List two human-made ecosystems. (ii) "We do not clean a pond in the same manner as we do in an aquarium." Give reason to justify this statement. **Part (i)** 1. Two human-made ecosystems are: Crop field and Aquarium. Answer (i): Crop field and aquarium **Part (ii)** 1. An aquarium is an artificial and incomplete ecosystem lacking natural self-sustaining food webs and decomposers. 2. A pond is a natural, self-sustaining ecosystem where natural recycling and cleansing mechanisms operate by themselves. Answer (ii): An aquarium is artificial and lacks the natural self-cleaning mechanisms and decomposers present in a natural pond ecosystem. **Answer:** Crop fields and aquariums are human-made ecosystems; a pond is a natural self-sustaining ecosystem whereas an aquarium is artificial and lacks natural decomposers and self-regulation. > Common mistake: Stating that aquariums need cleaning because they are bigger, instead of recognizing them as artificial, closed ecosystems. ## SECTION B Questions No. 8 to 13 are also short answer type questions. Each question carries 3 marks. ### Question 8 *3 marks · Short answer · Carbon and its Compounds* (a) List two advantages of adopting the atomic number of an element as the basis of classification of elements in the Modern Periodic Table. (b) Write the electronic configurations of the elements X (atomic number 13) and Y (atomic number 20). **Part (a)** 1. Atomic number resolves the anomaly regarding the position of isotopes as they have the same atomic number. 2. It clearly explains the periodic recurrence of properties based on the number of valence electrons. Answer (a): Isotopes are placed at the same position, and properties repeat due to identical valence shell electronic configurations. **Part (b)** 1. For element X with atomic number 13, the electronic configuration is $2, 8, 3$. 2. For element Y with atomic number 20, the electronic configuration is $2, 8, 8, 2$. Answer (b): Element X: 2, 8, 3 and Element Y: 2, 8, 8, 2 **Answer:** (a) Atomic number removes anomalies like position of isotopes; properties repeat periodically. (b) X: 2, 8, 3; Y: 2, 8, 8, 2. > Common mistake: Writing incorrect electronic configuration by exceeding shell capacities. ### Question 9 *3 marks · Short answer · Carbon and its Compounds* (a) Draw two different possible structures of a saturated hydrocarbon having four carbon atoms in its molecule. What are these two structures of the hydrocarbon having same molecular formula called ? Write the molecular formula and the common name of this compound. Also write the molecular formula of its alkyne. **Part (a)** 1. The two possible structures for $\text{C}_4\text{H}_{10}$ are straight-chain butane and branched-chain isobutane (2-methylpropane). 2. Compounds with the same molecular formula but different structures are called isomers. 3. The molecular formula is $\text{C}_4\text{H}_{10}$ and the common name is butane. 4. The molecular formula of the corresponding alkyne (butyne) is $\text{C}_4\text{H}_6$. Answer (a): Isomers: butane and isobutane; Molecular formula: $\text{C}_4\text{H}_{10}$; Common name: butane; Alkyne formula: $\text{C}_4\text{H}_6$ **Answer:** Structures: straight chain and branched chain (isomers). Molecular formula: $\text{C}_4\text{H}_{10}$, common name: butane. Alkyne formula: $\text{C}_4\text{H}_6$. > Common mistake: Confusing structural isomers with allotropes. ### Question 9 (OR) *3 marks · Short answer · Carbon and its Compounds* (b) (i) Write the molecular formula of benzene and draw its structure. (ii) Write the number of single and double covalent bonds present in a molecule of benzene. (iii) Which compounds are called alkynes ? **Part (i)** 1. The molecular formula of benzene is $\text{C}_6\text{H}_6$. 2. Its structure is a six-carbon ring with alternating single and double bonds. Answer (i): Molecular formula: $\text{C}_6\text{H}_6$; ring structure with alternating double bonds. **Part (ii)** 1. A molecule of benzene contains 6 carbon-carbon bonds and 6 carbon-hydrogen bonds. 2. In total, there are 9 single covalent bonds and 3 double covalent bonds. Answer (ii): 9 single covalent bonds and 3 double covalent bonds. **Part (iii)** 1. Unsaturated hydrocarbons which contain at least one carbon-carbon triple bond are called alkynes. Answer (iii): Unsaturated hydrocarbons with at least one triple bond. **Answer:** (i) $\text{C}_6\text{H}_6$, ring structure with alternating double bonds. (ii) 9 single bonds and 3 double bonds. (iii) Unsaturated hydrocarbons with a triple bond. > Common mistake: Counting incorrect number of bonds in benzene ring. ### Question 10 *3 marks · Short answer · How do Organisms Reproduce?* (a) Mention one function each of the following organs in human male reproductive system : (i) Testis (ii) Scrotum (iii) Vas deferens (iv) Prostate gland (b) Name the type of germ cell which (i) is motile, and (ii) stores food. **Part (a)** 1. (i) Testis: Produces male germ cells (sperms) and the hormone testosterone. 2. (ii) Scrotum: Provides a lower temperature than body temperature required for sperm production. 3. (iii) Vas deferens: Delivers the sperms from the testis to the urethra. 4. (iv) Prostate gland: Secretes fluid that makes the transport of sperms easier and provides nutrition. Answer (a): Functions of testis, scrotum, vas deferens, and prostate gland stated. **Part (b)** 1. (i) The male germ cell (sperm) is motile. 2. (ii) The female germ cell (egg/ovum) stores food. Answer (b): (i) Sperm (ii) Ovum **Answer:** (a) (i) Testis: Produce sperms and testosterone. (ii) Scrotum: Provides lower temperature for sperm formation. (iii) Vas deferens: Transfers sperms. (iv) Prostate gland: Secretes fluid to nourish and ease sperm transport. (b) (i) Sperm, (ii) Egg/Ovum. > Common mistake: Confusing the functions of male and female reproductive organs. ### Question 11 *3 marks · Short answer · Electricity* (a) Three resistors $R_1$, $R_2$ and $R_3$ are connected in parallel and the combination is connected to a battery, an ammeter, a voltmeter and a key. Draw suitable circuit diagram to show the arrangement of these circuit components along with the direction of current flowing. (b) Calculate the equivalent resistance of the following network: **Part (a)** 1. Draw a circuit diagram showing resistors $R_1$, $R_2$, and $R_3$ connected in parallel across a battery with a key, an ammeter in series, and a voltmeter across the parallel combination. 2. Indicate the direction of current from the positive to the negative terminal of the battery. Answer (a): Circuit diagram showing parallel combination with ammeter, voltmeter, and key. **Part (b)** 1. From the figure, $R_1 = 5\ \Omega$ and $R_4 = 5\ \Omega$ are in series with a parallel combination of $R_2 = 10\ \Omega$ and $R_3 = 10\ \Omega$. 2. The equivalent resistance of $R_2$ and $R_3$ in parallel is $\frac{10 \times 10}{10 + 10} = 5\ \Omega$. 3. Total equivalent resistance $R = R_1 + R_{\text{parallel}} + R_4 = 5 + 5 + 5 = 15\ \Omega$. Answer (b): $15\ \Omega$ **Answer:** Circuit diagram drawn with parallel resistors and series resistor. Equivalent resistance = $20\ \Omega$. > Common mistake: Misinterpreting the series and parallel connections in the given diagram network. ### Question 12 *3 marks · Numerical · Electricity* (a) (i) Define Electric Power and write its SI unit. (ii) Two bulbs rated $100\text{ W}; 220\text{ V}$ and $60\text{ W}; 220\text{ V}$ are connected in parallel to an electric mains of $220\text{ V}$. Find the current drawn by the bulbs from the mains. **Solution** 1. Given: Power of first bulb $P_1 = 100\text{ W}$, Voltage $V = 220\text{ V}$. 2. Given: Power of second bulb $P_2 = 60\text{ W}$, Voltage $V = 220\text{ V}$. 3. Formula: Total power in parallel $P = P_1 + P_2$. 4. Substitution: $P = 100\text{ W} + 60\text{ W} = 160\text{ W}$. 5. Formula: Current drawn $I = \frac{P}{V}$. 6. Substitution: $I = \frac{160\text{ W}}{220\text{ V}} = \frac{8}{11}\text{ A} \approx 0.73\text{ A}$. 7. Result: $0.73\text{ A}$. **Answer:** $0.73\text{ A}$ > Common mistake: Calculating currents separately and making calculation errors in fractions. ### Question 12 (OR) *3 marks · Numerical · Electricity* (b) (i) State Joule's law of heating. Express it mathematically when an appliance of resistance R is connected to a source of voltage V and the current I flows through the appliance for a time t. (ii) A $5\;\Omega$ resistor is connected across a battery of 6 volts. Calculate the energy that dissipates as heat in $10\text{ s}$. **Part (i)** 1. Joule's law of heating states that the heat produced in a resistor is directly proportional to the square of current for a given resistance, proportional to resistance for a given current, and proportional to the time for which the current flows through the resistor. 2. Mathematically, it is expressed as $H = I^2Rt$. Answer (i): $H = I^2Rt$ **Part (ii)** 1. Given: Resistance $R = 5\;\Omega$, Voltage $V = 6\text{ V}$, Time $t = 10\text{ s}$. 2. Formula: Current $I = \frac{V}{R} = \frac{6}{5} = 1.2\text{ A}$, and Heat energy $H = I^2Rt$. 3. Substitution: $H = (1.2)^2 \times 5 \times 10 = 1.44 \times 5 \times 10$. 4. Result: $72\text{ J}$. Answer (ii): 72 J **Answer:** The heat produced is $H = I^2Rt$ and the dissipated energy is $72\text{ J}$. > Common mistake: Forgetting to square the current in the heating formula or calculating current incorrectly. ### Question 13 *3 marks · Short answer · Our Environment* (a) Name the group of organisms which form in the first trophic level of all food chains. Why are they called so ? (b) Why are the human beings most adversely affected by bio-magnification ? (c) State one ill-effect of the absence of decomposers from a natural ecosystem. **Part (a)** 1. Producers (or autotrophs / green plants) form the first trophic level of all food chains. 2. They are called so because they can manufacture their own food using solar energy through photosynthesis. Answer (a): Producers, because they make their own food using sunlight. **Part (b)** 1. Human beings occupy the topmost position in most food chains. 2. Due to biological magnification, harmful chemicals and pesticides get accumulated in maximum concentration at the highest trophic level. Answer (b): Because humans occupy the top trophic level where toxic chemicals concentrate the most. **Part (c)** 1. In the absence of decomposers, the recycling of nutrients in the biosphere would not take place, leading to accumulation of dead organic matter. Answer (c): Nutrient recycling stops and dead organic matter accumulates. **Answer:** Producers form the first trophic level, humans suffer maximum bio-magnification due to being at the top of the food chain, and absence of decomposers stops nutrient recycling. > Common mistake: Confusing producers with consumers in the first trophic level. ## SECTION C Questions No. 14 and 15 are case-based questions. Each question carries 4 marks. ### Question 14 *4 marks · Case-based · Heredity* The mechanism by which the sex of an individual is determined is called sex-determination. In human beings, sex of a newborn is genetically determined, whereas in some others it is not. There are 46 (23 pairs) chromosomes in human beings. Out of these, 44 (22 pairs) control the body characters and 2 (one pair) are known as sex chromosomes. The sex chromosomes are of two types — X chromosome and Y chromosome. At the time of fertilisation, depending upon which type of male gamete fuses with the female gamete, the sex of the newborn child is decided. (a) Why is a pair of sex chromosomes in human beings called a mismatched pair in terms of type and size ? (b) Out of male or female, which of them has a perfect pair of sex chromosomes ? In case of a perfect pair, will the gametes produced be of the same kind or of a different kind ? (c) (i) Name two animals whose sex is not genetically determined. Explain the process of their sex determination. **Part (a)** 1. Human males have one X and one Y chromosome. 2. The Y chromosome is much shorter and structurally different compared to the X chromosome, hence it is called a mismatched pair. Answer (a): The XY pair is mismatched because the Y chromosome is significantly smaller than the X chromosome. **Part (b)** 1. Human females have a perfect pair of sex chromosomes represented as XX. 2. Since both sex chromosomes are identical, all gametes produced by females are of the same kind containing an X chromosome. Answer (b): Females have a perfect pair (XX), and the gametes produced are all of the same kind (carrying an X chromosome). **Part (c)(i)** 1. Animals such as some reptiles (e.g., turtles and lizards) do not have genetically determined sex. 2. In these animals, the temperature at which fertilized eggs are kept determines whether the developing animal will be male or female. Answer (c)(i): In some reptiles, sex is determined by environmental temperature rather than genetics. **Answer:** Sex determination in humans depends on the inheritance of X and Y chromosomes from the male parent. > Common mistake: Confusing male and female heterogamety or stating that temperature determines sex in all reptiles. ### Question 14 (OR) *4 marks · Case-based · Heredity* The mechanism by which the sex of an individual is determined is called sex-determination. In human beings, sex of a newborn is genetically determined, whereas in some others it is not. There are 46 (23 pairs) chromosomes in human beings. Out of these, 44 (22 pairs) control the body characters and 2 (one pair) are known as sex chromosomes. The sex chromosomes are of two types — X chromosome and Y chromosome. At the time of fertilisation, depending upon which type of male gamete fuses with the female gamete, the sex of the newborn child is decided. (a) Why is a pair of sex chromosomes in human beings called a mismatched pair in terms of type and size ? (b) Out of male or female, which of them has a perfect pair of sex chromosomes ? In case of a perfect pair, will the gametes produced be of the same kind or of a different kind ? (ii) With the help of a flowchart only, show how sex is genetically determined in human beings. **Part (a)** 1. Human males possess one X and one Y chromosome which are unequal in size. 2. Due to this difference in size and type, the XY combination is referred to as a mismatched pair. Answer (a): The XY pair is called mismatched because the Y chromosome is shorter than the X chromosome. **Part (b)** 1. Human females possess a pair of X chromosomes (XX), which is a perfect pair. 2. The gametes (ova) produced by females are all of the same kind, each containing a single X chromosome. Answer (b): Females have a perfect pair (XX) and produce gametes of the same kind. **Part (ii)** 1. Parents: Parents (XX Female $\times$ XY Male) 2. Gametes: Female produces (X), Male produces (X) or (Y) 3. Offspring: Fusion of X sperm with X egg gives XX (Female), and fusion of Y sperm with X egg gives XY (Male). Answer (ii): Flowchart showing equal probability of XX (female) and XY (male) offspring based on fertilising sperm. **Answer:** Sex in human beings is genetically determined by the type of sperm (X or Y) that fuses with the egg (X). > Common mistake: Omitting the chromosome types in the flowchart representation. ### Question 15 *4 marks · Case-based · Magnetic Effects of Electric Current* A student fixes a sheet of white paper on a drawing board using some adhesive materials. She places a bar magnet in the centre of it and sprinkles some iron filings uniformly around the bar magnet using a salt-sprinkler. On tapping the board gently, she observes that the iron filings have arranged themselves in a particular pattern. (a) Draw a diagram to show this pattern of iron filings. (b) Draw the magnetic field lines of a bar magnet showing the poles of the bar magnet as well as the direction of the magnetic field lines. (c) (i) How is the direction of magnetic field at a point determined using the field lines ? Why do two magnetic field lines not cross each other ? **Part (a)** 1. Iron filings align along the magnetic field lines when the drawing board is gently tapped. 2. The pattern shows concentration of iron filings near the poles of the bar magnet. Answer (a): Iron filings arrange themselves in concentric curved patterns representing magnetic field lines around the bar magnet. **Part (b)** 1. Draw closed loops emerging from the North pole and entering the South pole outside the magnet. 2. Inside the magnet, the field lines run from the South pole to the North pole with arrows marked accordingly. Answer (b): Field lines directed from North to South outside the magnet and South to North inside. **Part (c)(i)** 1. The direction of the magnetic field at any point is determined by drawing a tangent to the magnetic field line at that point. 2. Two magnetic field lines never cross each other because if they did, it would mean there are two directions of the magnetic field at the same point, which is physically impossible. Answer (c)(i): Direction is given by the tangent to the field line; lines do not cross because a compass needle cannot point in two directions at once. **Answer:** Magnetic field lines form continuous closed curves representing the direction and strength of the magnetic field. > Common mistake: Stating that field lines intersect or failing to show arrows inside and outside the magnet. ### Question 15 (OR) *4 marks · Case-based · Magnetic Effects of Electric Current* A student fixes a sheet of white paper on a drawing board using some adhesive materials. She places a bar magnet in the centre of it and sprinkles some iron filings uniformly around the bar magnet using a salt-sprinkler. On tapping the board gently, she observes that the iron filings have arranged themselves in a particular pattern. (a) Draw a diagram to show this pattern of iron filings. (b) Draw the magnetic field lines of a bar magnet showing the poles of the bar magnet as well as the direction of the magnetic field lines. (ii) How are the magnetic field lines of a bar magnet drawn using a small compass needle ? Draw one magnetic field line each on both sides of the magnet. **Part (a)** 1. Iron filings experience a force and arrange in definite curved patterns surrounding the bar magnet. 2. The pattern is densest near the poles. Answer (a): Iron filings form curved patterns outlining the magnetic field. **Part (b)** 1. Sketch closed continuous loops around the bar magnet indicating North and South poles. 2. Mark arrows pointing from North to South externally. Answer (b): Bar magnet field lines diagram with proper pole markings and directional arrows. **Part (ii)** 1. Place a small compass near the North pole of the bar magnet and mark the position of its north pointer. 2. Move the compass so that its south pole occupies the previous north position and repeat to trace a continuous line from North to South. Answer (ii): Field lines are plotted step-by-step by shifting a compass needle along the deflection path from pole to pole. **Answer:** Magnetic field lines can be mapped using a small compass needle placed near a bar magnet. > Common mistake: Reversing the direction of magnetic field lines or missing the compass plotting technique steps. ## Frequently asked questions ### What is the exam pattern and section breakdown for the CBSE Class 10 Science 2022 Set 31/1/1 paper? The question paper is divided into three sections with a total of 40 marks and a duration of 120 minutes. Section A contains 7 questions for 14 marks, Section B has 6 questions for 18 marks, and Section C consists of 2 questions for 8 marks. ### How are the marks distributed across the different sections in this question paper? Section A carries 14 marks across 7 questions, while Section B carries 18 marks across 6 questions. Section C provides the remaining 8 marks through 2 questions, making a total of 40 marks. ### Which chapters carry the highest weightage in the CBSE Class 10 Science 2022 Set 31/1/1 paper? Carbon and its Compounds carries the highest weightage with 10 marks, followed by How do Organisms Reproduce with 7 marks. Heredity, Magnetic Effects of Electric Current, and Electricity each carry 6 marks, while Our Environment carries 5 marks. ### How should students write answers to score full marks in this Science paper? Students should write clear step-by-step solutions, especially for numerical and chemical equation questions. Referring to the provided chapter-wise solutions helps understand the exact presentation required to secure maximum marks. ### Is the solutions PDF for the CBSE Class 10 Science 2022 Set 31/1/1 paper free to access? Yes, the complete solutions PDF for this 40-mark paper is entirely free to download on SwaVid. You can use it to check your answers and review the detailed chapter weightage. ## Related pages - [All CBSE Class 10 Science papers](https://www.swavid.com/cbse/class-10/science/previous-year-papers) Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student