Bihar Board Class 10 Science Question Paper 2025 (Code 212 Set-F) Available- Download Here with Solution PDF

The hormone that controls the symptoms of puberty in adolescents is

• (A) Thyroxine
• (B) Estrogen
• (C) Testosterone
• (D) None of these

At what stage of foetus does safe abortion occur?

• (A) Blastula
• (B) Organ formation
• (C) Mature embryo
• (D) None of these

Which of the following is an artificial ecosystem?

• (A) Park
• (B) Aquarium
• (C) Garden
• (D) All of these

Which substance cannot be decomposed in the environment?

• (A) Dry leaves
• (B) Food
• (C) Dead organism
• (D) Plastic

The correct food chain is

• (A) Fish \(\rightarrow\) Grass \(\rightarrow\) Cow
• (B) Goat \(\rightarrow\) Grass \(\rightarrow\) Deer
• (C) Grass \(\rightarrow\) Deer \(\rightarrow\) Lion
• (D) Bird \(\rightarrow\) Snake \(\rightarrow\) Grass

The substances which get decomposed by biological process are

• (A) Non-biodegradable
• (B) Inert
• (C) Biodegradable
• (D) None of these

Waste can be managed by which of the following?

• (A) Burning it out of the city
• (B) Using in filling pits
• (C) Recycling of some wastes
• (D) All of these

Which disease may primarily be caused in humans by ultraviolet (UV) rays of the Sun?

• (A) Lung cancer
• (B) Tuberculosis (T.B.)
• (C) Oral cancer
• (D) Skin cancer

Which quantity is electric potential?

• (A) Scalar quantity
• (B) Vector quantity
• (C) Both (A) and (B)
• (D) None of these

The action of an electric motor is based on

• (A) Electric current and magnetic effect
• (B) Rotation of armature
• (C) Both (A) and (B)
• (D) None of these

From which of the following does the induced current get direction?

• (A) By Lenz's law
• (B) By left hand rule
• (C) By right hand rule
• (D) By Ohm's law

The frequency of alternating electric current produced in India is

• (A) 80 Hz
• (B) 70 Hz
• (C) 60 Hz
• (D) 50 Hz

What will be the resistance of the wire when its length increases?

• (A) Decreases
• (B) Increases
• (C) Remains constant
• (D) None of these

The electrical resistivity of silver at 20\(^\circ\)C is

• (A) \(49 \times 10^{-6} \, \Omega m\)
• (B) \(1.60 \times 10^{-8} \, \Omega m\)
• (C) \(10^{12} \, \Omega m\)
• (D) \(6.84 \times 10^{-8} \, \Omega m\)

Which gas is not released when fossil fuels are burnt?

• (A) Oxygen gas
• (B) Carbon dioxide gas
• (C) Sulphur dioxide gas
• (D) None of these

Which of the following is the main component of biogas?

• (A) H\(_2\)S
• (B) H\(_2\)
• (C) CO\(_2\)
• (D) CH\(_4\)

Tincture iodine solution is prepared in

• (A) Ethyl alcohol
• (B) Chloroform
• (C) Carbon tetrachloride
• (D) Ether

The IUPAC name of CH\(_3\)CH\(_2\)CH\(_2\)OH is

• (A) 2-propanol
• (B) Propyl alcohol
• (C) 1-propanol
• (D) 3-propanol

Which of the following is liquid at room temperature?

• (A) Ethanol
• (B) Methane
• (C) Ethane
• (D) Ethyne

Benzene reacts with nitric acid in the presence of concentrated sulphuric acid to form

• (A) Nitrobenzene
• (B) Phenol
• (C) Toluene
• (D) Benzoic acid

Which of the following compounds can be used as fuel?

• (A) Ethanol
• (B) Propanol
• (C) Ethanoic acid
• (D) All of these

Which of the following groups form the Dobereiner’s triad?

• (A) N, P, As
• (B) F, Cl, Br
• (C) Ca, Sr, Ba
• (D) Be, Mg, Ca

The molecular formula of ozone is

• (A) O\(_2\)
• (B) O\(_3\)
• (C) O\(_4\)
• (D) O\(_5\)

How many bonds are found between the two atoms of a molecule of oxygen gas (O\(_2\))?

• (A) 1
• (B) 2
• (C) 3
• (D) None of these

Elements from group 13 to 18 are called

• (A) Elements of d-block
• (B) Elements of p-block
• (C) Elements of s-block
• (D) Elements of f-block

Which of the following elements has the highest number of valence electrons?

• (A) Al
• (B) P
• (C) Na
• (D) Si

Which of the following is a pollution-free source of energy?

• (A) Solar energy
• (B) Hydro-electric energy
• (C) Wind energy
• (D) All of these

Which of the following is responsible for the depletion of the ozone layer?

• (A) Sulphur
• (B) Carbon dioxide
• (C) Carbon
• (D) Chlorofluorocarbon

‘Ahar and Pyne’ is the water harvesting system of which state?

• (A) Bihar
• (B) Uttar Pradesh
• (C) Maharashtra
• (D) Madhya Pradesh

Which of the following is a natural resource?

• (A) Soil
• (B) Water
• (C) Air
• (D) All of these

Which of the following is a forest-based industry?

• (A) Lac industry
• (B) Paper industry
• (C) Timber industry
• (D) All of these

We can get iodine in adequate quantity from which of the following?

• (A) Rice
• (B) Salt
• (C) Sugar
• (D) None of these

Which of the following is the primary source of energy in fossil fuels?

• (A) Moon
• (B) Nuclear fusion
• (C) Sun
• (D) None of these

In which of the following forms is energy available in the oceans?

• (A) Tidal energy
• (B) Wave energy
• (C) Oceanic thermal energy
• (D) All of these

In which state is Tarapur Nuclear Power Plant located?

• (A) Rajasthan
• (B) Gujarat
• (C) Maharashtra
• (D) Bihar

The substances that take part in a reaction are called

• (A) Reducing agents
• (B) Reactants
• (C) Oxidising agents
• (D) Products

The reaction, in which heat is also generated along with the formation of product, is called

• (A) Endothermic
• (B) Oxidation
• (C) Photosynthesis
• (D) Exothermic

Oxidation is a reaction in which there is

• (A) Dissociation of hydrogen
• (B) Loss of electrons
• (C) Addition of oxygen
• (D) All of these

Which of the following is a synthetic indicator?

• (A) Turmeric
• (B) Litmus paper
• (C) Methyl orange
• (D) Red cabbage

Which substance turns red litmus paper blue in aqueous solution?

• (A) Alkali
• (B) Acid
• (C) Salt
• (D) None of these

Oiled paper is

• (A) Opaque
• (B) Transparent
• (C) Translucent
• (D) None of these

Which of the following is the beam of light coming from the Sun?

• (A) Converged light beam
• (B) Parallel light beam
• (C) Diverged light beam
• (D) All of these

Which of the following is the imaginary (virtual) image formed in a convex mirror?

• (A) Inverted and magnified
• (B) Straight and small
• (C) Straight and magnified
• (D) None of these

Which of the following is the mirror formula?

• (A) \(\dfrac{1}{v} - \dfrac{1}{u} = \dfrac{1}{f}\)
• (B) \(\dfrac{1}{f} + \dfrac{1}{u} = \dfrac{1}{v}\)
• (C) \(\dfrac{1}{f} - \dfrac{1}{v} = \dfrac{1}{u}\)
• (D) \(\dfrac{1}{f} = \dfrac{1}{v} + \dfrac{1}{u}\)

How does a virtual image look like?

• (A) Inverted
• (B) Erect
• (C) Both (A) and (B)
• (D) None of these

Which of the following mirrors has a positive focal length?

• (A) Convex mirror
• (B) Plane mirror
• (C) Concave mirror
• (D) None of these

Which of the following is the focal length of a convex mirror whose radius of curvature is 32 cm?

• (A) -8 cm
• (B) +8 cm
• (C) -16 cm
• (D) +16 cm

Which of the following is a magnifying glass?

• (A) Concave mirror
• (B) Concave lens
• (C) Convex lens
• (D) None of these

The chemical formula of bleaching powder is

• (A) CaO
• (B) CaCl\(_2\)
• (C) CaOCl
• (D) CaOCl\(_2\)

The ratio of HCl and HNO\(_3\) in aqua regia is

• (A) 2 : 2
• (B) 1 : 2
• (C) 1 : 3
• (D) 3 : 1

What type of salt is Pb(OH)NO\(_3\)?

• (A) Common salt
• (B) Mixed salt
• (C) Acidic salt
• (D) Basic salt

The ratio of nitrogen and hydrogen atoms in one molecule of ammonia is

• (A) 1 : 3
• (B) 3 : 1
• (C) 1 : 2
• (D) 2 : 1

Which of the following is the most acidic oxide?

• (A) CaO
• (B) MgO
• (C) Na\(_2\)O
• (D) SO\(_2\)

Which of the elements represented by the following symbols is a metal?

• (A) \(^{16}_{8}A\)
• (B) \(^{19}_{9}B\)
• (C) \(^{24}_{12}C\)
• (D) \(^{12}_{6}D\)

An alloy of mercury and another metal is called

• (A) Bronze
• (B) Solder
• (C) Brass
• (D) Amalgam

Which of the following is an allotrope of carbon?

• (A) Diamond
• (B) Fullerene
• (C) Graphite
• (D) All of these

In which lens can both real and virtual images be formed?

• (A) Convex lens
• (B) Concave lens
• (C) Both (A) and (B)
• (D) None of these

How many colours are there in white light?

• (A) 1
• (B) 3
• (C) 5
• (D) 7

Which colour of white light bends the least after passing through a prism?

• (A) Blue
• (B) Red
• (C) Violet
• (D) Yellow

Which of the following controls the size of the pupil?

• (A) Eye lens
• (B) Retina
• (C) Iris
• (D) Ciliary muscles

Which lens is used in nearsightedness (myopia)?

• (A) Convex lens
• (B) Cylindrical lens
• (C) Concave lens
• (D) None of these

Which of the following is the formula to find the resistance of a coil?

• (A) \(R = V - I\)
• (B) \(R = \dfrac{V}{I}\)
• (C) \(R = V \times I\)
• (D) \(R = \dfrac{I}{V}\)

The SI unit of resistance is

• (A) coulomb
• (B) joule
• (C) ampere
• (D) ohm

Which of the following is the commercial unit of electrical energy?

• (A) watt/hour
• (B) unit
• (C) watt
• (D) none of these

Which of the following is a vestigial organ in the human alimentary canal?

• (A) Appendix
• (B) Colon
• (C) Caecum
• (D) Rectum

The length of the small intestine in herbivorous animals is

• (A) Small
• (B) Medium
• (C) Longer
• (D) None of these

The completely digested food in the small intestine is called

• (A) Chyme
• (B) Chile
• (C) Chylomicron
• (D) None of these

By which method is water absorbed by root hairs?

• (A) Transfer
• (B) Diffusion
• (C) Osmosis
• (D) Both (A) and (B)

The condition of high blood pressure is called

• (A) Paralysis
• (B) Hypotension
• (C) Hypertension
• (D) None of these

How many pairs of respiratory pores are found in a cockroach?

• (A) 2
• (B) 6
• (C) 8
• (D) 10

The flow of blood in the heart is

• (A) From left atrium to left ventricle
• (B) From right atrium to right ventricle
• (C) From right atrium to left ventricle
• (D) Both (A) and (B)

Blood is

• (A) Nervous tissue
• (B) Epithelial tissue
• (C) Connective tissue
• (D) Muscular tissue

Which blood group is known as universal donor?

• (A) A
• (B) B
• (C) O
• (D) AB

The process of purification of blood by dialysis machine is called

• (A) Dialyzer
• (B) Haemodialysis
• (C) Dialysate
• (D) Cellophane

How do protozoans expel excretory substances?

• (A) By absorption
• (B) By expulsion
• (C) By osmosis
• (D) By diffusion

Which excretory substance is mainly released from acacia plants?

• (A) Resin
• (B) Tannin
• (C) Latex
• (D) Gum

Which is the largest part of the human brain?

• (A) Cerebellum
• (B) Cerebrum
• (C) Medulla oblongata
• (D) None of these

Testosterone is secreted by

• (A) Ovary
• (B) Testis
• (C) Kidney
• (D) None of these

Hormone that stops cell division in plants is called

• (A) Auxin
• (B) Ethylene
• (C) Cytokinin
• (D) Abscisic acid

The male reproductive organ of a flower is called

• (A) Gynoecium
• (B) Petal
• (C) Stamens
• (D) None of these

What is light beam? How many types of it are there?

Why does the coin placed in water appear raised?

Write the main differences between stars and planets.

How does an electromagnet work?

What is nuclear fusion?

What is electric current? Write its equation and unit.

What is fossil fuel? Write with example.

What are renewable and non-renewable sources?

Describe Oersted's experiment to show that a magnetic field is produced around a current carrying conductor wire.

Describe a method to find the focal length of a convex lens.

Why does the colour of the solution change when a piece of iron is added to copper sulphate solution?

Why is it necessary to keep the plaster of Paris away from moisture? Explain.

What are acids? Give any two examples. Explain the effect of an acid on an indicator.

Why is sodium metal kept immersed in kerosene?

Which metallic property does graphite exhibit despite being a non-metal?

What are aliphatic compounds?

What do you understand by homologous series? Write with examples.

What are the benefits of a dam?

Explain the importance of pH in daily life.

What should be done for water conservation and water management?

Write four main characteristics of living beings.

Why does continuous running cause cramps to a person’s muscles?

What is the importance of blood platelets?

Write the names of some excretory substances of plants.

Write the names of endocrine glands found in humans.

What is the difference between menarche and menopause?

What is the meaning of biological evolution?

What is the role of decomposers in the ecosystem?

Draw a neat labelled diagram of the respiratory organs of human being.

Write the functions of liver.