Bihar Board Class 10 · Science · Matric exam 2027
Bihar Board Class 10 Science Question Paper 2024
The board’s 2024 question paper, set G — all 110 questions as printed; 80 objective answers from the board’s own key; full model answers for 3 written questions, how the answer begins for 27 more. Each question names its chapter, where that chapter’s most-asked questions are.
Full marks 80 · Time 2 h 45 min
Section A · Objective questions (80)
The magnification produced by a concave mirror of focal length 10 cm is positive, if the value of object distance is
- (A) more than 10 cm
- (B) more than 20 cm
- (C) less than 10 cm ✓
- (D) none of these
Answer (the board’s key): (C)
On moving from focus towards the pole, the magnification in a concave mirror
- (A) increases
- (B) decreases ✓
- (C) remains constant
- (D) none of these
Answer (the board’s key): (B)
Which energy does a hydro-electric power plant convert into electric energy?
- (A) Nuclear energy
- (B) Solar energy
- (C) Potential energy ✓
- (D) Thermal energy
Answer (the board’s key): (C)
A rectangular coil of a copper wire is rotated in a magnetic field. The direction of the induced current in the coil changes after
- (A) every one-fourth rotation
- (B) every half rotation ✓
- (C) every one rotation
- (D) every two rotations
Answer (the board’s key): (B)
The image of an ant in a concave mirror is erect and goes on increasing as the ant moves along the principal axis. The direction of motion of the ant is
- (A) from focus to centre of curvature
- (B) from focus to pole
- (C) from pole to focus ✓
- (D) none of these
Answer (the board’s key): (C)
The radius of curvature of the lens of an eye is controlled by
- (A) retina
- (B) iris
- (C) pupil
- (D) ciliary muscles ✓
Answer (the board’s key): (D)
Why is the colour of some clouds white ?
- (A) Due to reflection
- (B) Due to scattering ✓
- (C) Due to absorption
- (D) Due to refraction
Answer (the board’s key): (B)
The SI unit of resistance is
- (A) ampere
- (B) watt
- (C) ohm ✓
- (D) volt
Answer (the board’s key): (C)
Depletion of ozone layer is due to
- (A) ATP
- (B) CFC ✓
- (C) NADP
- (D) DDT
Answer (the board’s key): (B)
In which of the following organisms does asexual reproduction occur through budding ?
- (A) Plasmodium
- (B) Leishmania
- (C) Amoeba
- (D) Yeast ✓
Answer (the board’s key): (D)
An example of plant hormone is
- (A) IAA ✓
- (B) TSH
- (C) ACH
- (D) ACTH
Answer (the board’s key): (A)
Vegetative propagation in potato takes place by
- (A) root
- (B) seed
- (C) fruit
- (D) stem ✓
Answer (the board’s key): (D)
Hydrilla is found
- (A) in water ✓
- (B) in soil
- (C) on tree
- (D) all of these
Answer (the board’s key): (A)
Systolic blood pressure of a healthy person is
- (A) 140 mm Hg
- (B) 120 mm Hg ✓
- (C) 100 mm Hg
- (D) 80 mm Hg
Answer (the board’s key): (B)
An example of bisexual organism is
- (A) Hydra ✓
- (B) Man
- (C) Fish
- (D) Goat
Answer (the board’s key): (A)
In fish, respiration takes place through
- (A) mouth
- (B) gills ✓
- (C) nose
- (D) lungs
Answer (the board’s key): (B)
Kilowatt-hour (kWh) is the unit of
- (A) energy ✓
- (B) time
- (C) mass
- (D) power
Answer (the board’s key): (A)
The amount of light entering in human eye is controlled by
- (A) ciliary muscles
- (B) pupil ✓
- (C) cornea
- (D) iris
Answer (the board’s key): (B)
Which is the conventional source of energy ?
- (A) Nuclear energy source
- (B) Geo-thermal energy source
- (C) Biomass ✓
- (D) None of these
Answer (the board’s key): (C)
The maximum number of electrons in a shell is
- (A) 4n^2
- (B) 3n^2
- (C) 2n^2 ✓
- (D) n^2
Answer (the board’s key): (C)
Which hydrocarbon is the simplest compound ?
- (A) Methane ✓
- (B) Propane
- (C) Butane
- (D) Ethane
Answer (the board’s key): (A)
Which of the following metals has the lowest melting point ?
- (A) Na ✓
- (B) Cu
- (C) Fe
- (D) Al
Answer (the board’s key): (A)
The atomic number of gold is
- (A) 23
- (B) 43
- (C) 79 ✓
- (D) 80
Answer (the board’s key): (C)
Which of the following is a salt ?
- (A) HCl
- (B) NH4OH
- (C) NaOH
- (D) K2SO4 ✓
Answer (the board’s key): (D)
The expulsion of water through stomata in the form of vapour from the aerial part of the plant is known as
- (A) osmosis
- (B) transpiration ✓
- (C) excretion
- (D) diffusion
Answer (the board’s key): (B)
The tiger is a consumer of
- (A) first trophic level
- (B) second trophic level
- (C) third trophic level ✓
- (D) none of these
Answer (the board’s key): (C)
The place of origin of human is
- (A) India
- (B) China
- (C) Africa ✓
- (D) America
Answer (the board’s key): (C)
Peristalsis movement is found in
- (A) Colon
- (B) Oesophagus ✓
- (C) Pancreas
- (D) Small intestine
Answer (the board’s key): (B)
Open circulatory system is found in
- (A) pigeon
- (B) butterfly ✓
- (C) man
- (D) cat
Answer (the board’s key): (B)
The carrier of oxygen in blood is
- (A) fat
- (B) hormone
- (C) haemoglobin ✓
- (D) carbohydrate
Answer (the board’s key): (C)
The number of pairs of autosomes in human is
- (A) 24
- (B) 23
- (C) 11
- (D) 22 ✓
Answer (the board’s key): (D)
The most effective colour of visible light spectrum for photosynthesis is
- (A) red ✓
- (B) blue
- (C) yellow
- (D) green
Answer (the board’s key): (A)
The valency of all elements in a group of the periodic table is
- (A) same ✓
- (B) different
- (C) both (A) and (B)
- (D) none of these
Answer (the board’s key): (A)
Which of the following is used as wine ?
- (A) Ethanol ✓
- (B) Methanol
- (C) Vinegar
- (D) Methanoic acid
Answer (the board’s key): (A)
What is the number of elements in the third group of the period table ?
- (A) 18
- (B) 12
- (C) 10
- (D) 8 ✓
Answer (the board’s key): (D)
Which is used in Solar cell ?
- (A) Uranium
- (B) Plastic
- (C) Silicon ✓
- (D) Plutonium
Answer (the board’s key): (C)
The electronic configuration of an element is 2, 8, 7. What is the atomic number of the element ?
- (A) 10
- (B) 11
- (C) 17 ✓
- (D) 19
Answer (the board’s key): (C)
Duralumin is an alloy of which metal ?
- (A) Fe
- (B) Sn
- (C) Al ✓
- (D) Cu
Answer (the board’s key): (C)
The molecular formula of sodium phosphate is
- (A) NaPO4
- (B) Na3PO4 ✓
- (C) Na2(PO4)3
- (D) Na2PO4
Answer (the board’s key): (B)
The structural and functional unit of kidney is called
- (A) Urinary bladder
- (B) Glomerulus
- (C) Bowman's capsule
- (D) Nephron ✓
Answer (the board’s key): (D)
What should be the minimum speed of wind in a wind elect generator ?
- (A) 1500 km/h
- (B) 150 km/h
- (C) 15 km/h ✓
- (D) 1.5 km/h
Answer (the board’s key): (C)
A split ring is used in
- (A) galvanometer
- (B) D.C. motor ✓
- (C) microscope
- (D) none of these
Answer (the board’s key): (B)
Metallic conduction is based on motion of which particle in material?
- (A) Electron ✓
- (B) Proton
- (C) Neutron
- (D) None of these
Answer (the board’s key): (A)
The upper part of a box-type solar cooker has a glass cover. The reason for this is
- (A) to see whether the food kept inside the cooker is being cooked or not
- (B) to prevent loss of heat due to radiation ✓
- (C) to prevent the passage of dust into the box
- (D) none of these
Answer (the board’s key): (B)
A resistor of power P_1 at voltage of V_1 is connected in series with another resistor of power P_2 at voltage V_2. The equivalent resistance will be
- (A) V_1^2/P_1 + V_2^2/P_2 ✓
- (B) P_1^2/V_1 + P_2^2/V_2
- (C) (P_1 + P_2) / (V_1 + V_2)^2
- (D) P_1/V_1^2 + P_2/V_2^2
Answer (the board’s key): (A)
The frequency of alternating current in household electric circuit is
- (A) 50 Hz ✓
- (B) 60 Hz
- (C) 100 Hz
- (D) 220 Hz
Answer (the board’s key): (A)
Which of the following has the lowest refractive index ?
- (A) Turpentine
- (B) Benzene
- (C) Water ✓
- (D) Kerosine
Answer (the board’s key): (C)
A simple prism is bounded by how many surfaces ?
- (A) 3
- (B) 4
- (C) 5 ✓
- (D) 6
Answer (the board’s key): (C)
Kidney helps in
- (A) respiration
- (B) reproduction
- (C) excretion ✓
- (D) digestion
Answer (the board’s key): (C)
Photosynthesis takes place during
- (A) Morning-evening
- (B) Day only ✓
- (C) Day-night
- (D) Night only
Answer (the board’s key): (B)
Synaptic knobs are found in
- (A) kidney
- (B) brain
- (C) ovary
- (D) neuron ✓
Answer (the board’s key): (D)
Which of the following has the fastest heartbeat ?
- (A) Elephant
- (B) Human
- (C) Rat ✓
- (D) Whale
Answer (the board’s key): (C)
Which of the following is cellular fuel ?
- (A) Protein
- (B) Glucose ✓
- (C) Fat
- (D) None of these
Answer (the board’s key): (B)
How many phosphates are there in ATP ?
- (A) 1
- (B) 2
- (C) 3 ✓
- (D) 4
Answer (the board’s key): (C)
Which of the following is not an excretory organ of human ?
- (A) Lungs
- (B) Kidney
- (C) Pancreas ✓
- (D) Skin
Answer (the board’s key): (C)
The smallest endocrine gland is
- (A) Adrenal
- (B) Thyroid
- (C) Pineal ✓
- (D) None of these
Answer (the board’s key): (C)
All acids dissolve in water to give
- (A) H+ ion ✓
- (B) OH- ion
- (C) electron
- (D) neutron
Answer (the board’s key): (A)
Which of the following compounds is a weak acid ?
- (A) HCl
- (B) CH_3COOH ✓
- (C) H_2SO_4
- (D) HNO_3
Answer (the board’s key): (B)
What is the colour of silver iodide ?
- (A) White
- (B) Blue
- (C) Yellow ✓
- (D) Green
Answer (the board’s key): (C)
The hardest natural substance is
- (A) Silver
- (B) Gold
- (C) Diamond ✓
- (D) Iron
Answer (the board’s key): (C)
How many crystalline allotropes of carbon are there ?
- (A) 1
- (B) 2
- (C) 3 ✓
- (D) 4
Answer (the board’s key): (C)
Zinc blende is an ore of which metal ?
- (A) Mg
- (B) Zn ✓
- (C) Pb
- (D) Au
Answer (the board’s key): (B)
How many bonds are there between two atoms in a nitrogen ?
- (A) 1
- (B) 2
- (C) 3 ✓
- (D) 4
Answer (the board’s key): (C)
The general formula of alkyne is
- (A) C_nH_{2n+2}
- (B) C_nH_{2n}
- (C) C_nH_{2n-2} ✓
- (D) C_nH_{2n-1}
Answer (the board’s key): (C)
The far point for the normal vision is
- (A) 25 mm
- (B) 25 cm
- (C) 25 m
- (D) infinity ✓
Answer (the board’s key): (D)
What will be the nature of the image of an object, if magnification of the image is negative ?
- (A) Real and erect
- (B) Virtual and erect
- (C) Virtual and inverted
- (D) Real and inverted ✓
Answer (the board’s key): (D)
How many laws are there for reflection of light ?
- (A) 1
- (B) 2 ✓
- (C) 3
- (D) 4
Answer (the board’s key): (B)
A ray of light is incident perpendicular to a plane mirror. The angle of reflection will be
- (A) 135°
- (B) 90°
- (C) 45°
- (D) 0° ✓
Answer (the board’s key): (D)
Which colour of light scatters more in atmosphere ?
- (A) Yellow
- (B) Orange
- (C) Red
- (D) Blue ✓
Answer (the board’s key): (D)
Converging lens in air is
- (A) Concave lens of glass
- (B) Plano-concave lens of glass
- (C) Convex lens of glass ✓
- (D) none of these
Answer (the board’s key): (C)
If the lower half of a concave mirror gets broken then the image
- (A) will form erect
- (B) will be halved
- (C) will be less intense ✓
- (D) none of these
Answer (the board’s key): (C)
When a ray of light travels from air ( a rarer medium ) to glass ( denser medium ), it bends
- (A) away from the normal
- (B) towards the normal ✓
- (C) parallel to the normal
- (D) none of these
Answer (the board’s key): (B)
Which one of the following is the natural source of oxalic acid ?
- (A) Tomato ✓
- (B) Tamarind
- (C) Orange
- (D) Vinegar
Answer (the board’s key): (A)
Propane, with the molecular formula C_3H_8 has
- (A) 7 covalent bonds
- (B) 8 covalent bonds
- (C) 9 covalent bonds
- (D) 10 covalent bonds ✓
Answer (the board’s key): (D)
Ozone layer protects earth from which harmful radiation ?
- (A) Infrared
- (B) Thermal
- (C) Ultraviolet ✓
- (D) All of these
Answer (the board’s key): (C)
Which non-metal is found in liquid state at room temperature ?
- (A) Mercury
- (B) Bromine ✓
- (C) Sulphur
- (D) Sodium
Answer (the board’s key): (B)
Which one of the following is a metalloid ?
- (A) Fe
- (B) Cu
- (C) Ni
- (D) As ✓
Answer (the board’s key): (D)
CaCO3(s) -> CaO(s) + CO2(g) is what type of reaction ?
- (A) Decomposition ✓
- (B) Combination
- (C) Displacement
- (D) Double displacement
Answer (the board’s key): (A)
Which of the following equations is balanced ?
- (A) Mg + O2 -> MgO
- (B) Zn + H2SO4 -> ZnSO4 + H2 ✓
- (C) Fe + Cl2 -> FeCl3
- (D) H2 + Cl2 -> HCl
Answer (the board’s key): (B)
Which of the following causes acid rain in industrial areas ?
- (A) Chlorofluorocarbon
- (B) Sulphur dioxide ✓
- (C) Ozone
- (D) Carbon dioxide
Answer (the board’s key): (B)
Section B · Written questions (30)
Draw a labelled diagram of electric bulb.
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Model answer · labelled diagram, electric bulb
- 1.The labelled diagram of an electric bulb is drawn below showing its main parts.1 mark
- 2.The electric bulb consists of a glass bulb enclosing a filament made of tungsten, which is connected to two terminals through a base contact that fits into the socket for making the circuit connection.1 mark
Diagram: Draw an electric bulb showing: the glass bulb (outer glass covering), the filament (tungsten) inside, the two terminals/lead wires connecting the filament, and the base contact (metal base) at the bottom through which the terminals pass.
- Draw a clear outline of the glass bulb and mark the filament inside it with a label.
- Label the base contact and the terminals where the connecting wires attach.
- Write 'tungsten' next to the filament since the book states tungsten is used for filaments.
Marks split from a structure derived from past papers (checked twice); not Bihar Board’s official scheme
What is persistence of vision ?
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Model answer · persistence of vision
- 1.The impression of an image formed on the retina persists on the brain for about 1/16th of a second even after the object is removed from the eye.1 mark
- 2.This ability of vision is known as persistence of vision.1 mark
- Mention the exact time '1/16th of a second' in the first paragraph.
- End with the term 'persistence of vision' as the name of this ability.
Marks split from a structure derived from past papers (checked twice); not Bihar Board’s official scheme
Draw a ray diagram to show refraction of ray of light at both the refractive surfaces of a prism placed in air.
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Model answer · ray diagram, refraction through prism
- 1.A ray of light PE is incident on the refracting surface AB of the prism at angle of incidence ∠i. It bends towards the normal and travels inside the glass as the refracted ray EF at angle of refraction ∠r, bending towards the base of the prism.1 mark
- 2.The diagram is labelled with PE as the incident ray, EF as the refracted ray, FS as the emergent ray, ∠i as the angle of incidence, ∠r as the angle of refraction, ∠e as the angle of emergence, and ∠D as the angle of deviation between the incident ray and the emergent ray.1 mark
Diagram: Draw a triangular prism ABC with a ray PE incident on face AB; draw the normal at E, show the refracted ray EF inside the prism bending towards the base BC, draw the normal at F on face AC, and show the emergent ray FS bending away from the normal; label PE as incident ray, EF as refracted ray, FS as emergent ray, ∠i as angle of incidence, ∠r as angle of refraction, ∠e as angle of emergence, and ∠D as angle of deviation between the incident ray PE extended and the emergent ray FS.
- Show the refracted ray bending towards the base of the prism, not the apex.
- Label PE, EF, FS, ∠i, ∠r, ∠e and ∠D exactly on the diagram.
- Mark ∠D between the incident ray and the emergent ray.
Marks split from a structure derived from past papers (checked twice); not Bihar Board’s official scheme
What do you mean by power of lens ? Write its SI unit.
How the model answer begins
1. The power of a lens is the measure of the degree of convergence or divergence of light rays falling on it. The power of a lens is defined as the reciprocal of its focal length, that is, P = 1/f.
The full answer from Medha Ma’am →What is a simple microscope ? Draw its ray diagram.
How the model answer begins
1. A simple microscope is a convex lens of short focal length which is used to see small objects in a magnified form.
The full answer from Medha Ma’am →What is the law of refraction of light ?
How the model answer begins
1. The incident ray, the refracted ray and the normal to the interface of two transparent media at the point of incidence, all lie in the same plane.
The full answer from Medha Ma’am →What do you understand by 'short-circuit' ?
How the model answer begins
1. When the live wire and the neutral wire come into direct contact in an electric circuit, the resistance of the circuit becomes very low.
The full answer from Medha Ma’am →How is the resistance of a wire affected by its area of cross-section ?
How the model answer begins
1. The resistance of a uniform metallic conductor is inversely proportional to the area of cross-section (A) of the conductor, that is, R ∝ 1/A.
The full answer from Medha Ma’am →Define focus of a concave spherical mirror. Prove that in a concave mirror R = 2f.
How the model answer begins
1. The point on the principal axis where light rays parallel to the principal axis converge after reflection is called the principal focus of a concave mirror. It is represented by the letter F, and the distance between…
The full answer from Medha Ma’am →Explain conductor, insulator and semiconductor with examples.
How the model answer begins
1. Materials through which electric charge flows easily are called conductors. A component of a given size that offers a low resistance is a good conductor, because the electrons within it are only slightly restrained by…
The full answer from Medha Ma’am →Write the balanced chemical equations for the following reactions : (a) Zinc + Silver nitrate -> Zinc nitrate + Silver (b) Sodium + Water -> Sodium hydroxide + Hydrogen
How the model answer begins
1. The balanced chemical equation for zinc reacting with silver nitrate is Zn + 2AgNO3 → Zn(NO3)2 + 2Ag.
The full answer from Medha Ma’am →What are the essential steps for forest conservation ?
How the model answer begins
1. It is necessary to stop deforestation, because cutting down of forests causes loss of biodiversity and ecological instability. Large-scale afforestation should be carried out so that the forest cover is restored and…
The full answer from Medha Ma’am →Why does carbon mainly form covalent compounds ?
How the model answer begins
1. Carbon mainly forms covalent compounds because carbon has four electrons in its outermost shell and needs to gain or lose four electrons to attain noble gas configuration. Instead of forming C4– by gaining four…
The full answer from Medha Ma’am →What is the difference between displacement and double displacement reactions ? Write equations for these reactions.
How the model answer begins
1. In a displacement reaction, a more reactive element displaces a less reactive element from its compound.
The full answer from Medha Ma’am →Name the sodium compound which is used for softening hard water.
How the model answer begins
1. Sodium carbonate is the sodium compound used for removing permanent hardness of water. It is also called washing soda and its chemical formula is Na2CO3.
The full answer from Medha Ma’am →What is Anodising ?
How the model answer begins
1. Anodising is a process of forming a thick oxide layer of aluminium. Aluminium develops a thin oxide layer when exposed to air, and this oxide coat makes it resistant to further corrosion. The resistance can be improved…
The full answer from Medha Ma’am →Write two differences between minerals and ores.
How the model answer begins
1. Minerals are elements or compounds occurring naturally in the earth's crust, whereas ores are those minerals from which a metal can be extracted conveniently and profitably.
The full answer from Medha Ma’am →The aqueous solution of sodium carbonate is alkaline. Why ?
How the model answer begins
1. Sodium carbonate is a salt of a strong base and a weak acid, as it is formed from the reaction of a strong base, sodium hydroxide, and a weak acid, carbonic acid.
The full answer from Medha Ma’am →Write down the laboratory method of preparation of methane and its chemical reaction with chlorine.
How the model answer begins
1. A mixture of sodium acetate and soda lime (NaOH + CaO) is heated in a test tube to give methane gas.
The full answer from Medha Ma’am →What is the effect of deforestation on wildlife ?
How the model answer begins
1. Deforestation leads to the destruction of the natural habitats of wild animals. When forests are cut down, the trees, plants and other vegetation that make up the natural habitat of wild animals are removed, so the…
The full answer from Medha Ma’am →Write the importance of reproduction in living beings.
How the model answer begins
1. Reproduction is important because it allows organisms to maintain the continuity of their species. Populations of organisms fill well-defined places, or niches, in the ecosystem, using their ability to reproduce.…
The full answer from Medha Ma’am →Explore the difference between blood and lymph.
How the model answer begins
1. Blood is a red coloured fluid connective tissue which contains haemoglobin. It consists of a fluid medium called plasma in which the cells are suspended, and it transports food, oxygen, carbon dioxide and nitrogenous…
The full answer from Medha Ma’am →What is external respiration ?
How the model answer begins
1. External respiration is the process in which organisms take in oxygen from the environment and release carbon dioxide. Terrestrial animals breathe the oxygen present in the atmosphere, while aquatic animals use the…
The full answer from Medha Ma’am →Why do we sweat in summer ?
How the model answer begins
1. We sweat in summer because the sweat glands present in our skin become active when the body temperature rises during hot days. This happens because the body needs to prevent excessive rise of body temperature, so the…
The full answer from Medha Ma’am →What is photosynthesis ? Write the equation of its chemical reaction.
How the model answer begins
1. Photosynthesis is the process by which green plants make their own food (glucose) using carbon dioxide and water in the presence of sunlight and chlorophyll.
The full answer from Medha Ma’am →What is bio-magnification ?
How the model answer begins
1. The increase in the concentration of harmful chemicals or pollutants at each trophic level in a food chain is called biological magnification. As human beings occupy the top level in any food chain, the maximum…
The full answer from Medha Ma’am →What is the role of stomata and lenticels in respiration ?
How the model answer begins
1. Stomata are tiny pores present on the surface of the leaves. They facilitate gaseous exchange, allowing oxygen to enter and carbon dioxide to leave the cells during respiration. These pores also help in transpiration,…
The full answer from Medha Ma’am →What is ascent of sap ?
How the model answer begins
1. Ascent of sap is the upward movement of water and dissolved minerals absorbed by plant roots through xylem vessels.
The full answer from Medha Ma’am →Draw a labelled diagram of human digestive system and explain the digestive process of food.
How the model answer begins
1. The human digestive system consists of the alimentary canal, which is basically a long tube extending from the mouth to the anus, along with associated glands. The diagram given below shows the mouth, oesophagus…
The full answer from Medha Ma’am →What is a food chain ? Explain it with an example.
How the model answer begins
1. The process of transfer of energy from one organism to another is called a food chain. The series of organisms taking part at various biotic levels, each feeding upon the one before it, forms this food chain. Each step…
The full answer from Medha Ma’am →
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