Class 10 Science Important MCQ — Chapter Wise (2026-27)

Updated

Chapter-wise objective practice for CBSE Class 10 Science, checked question by question against the 2026-27 syllabus. Nothing here tests a topic that has been dropped. 73 objective questions across 12 chapters.

All Class 10 Science practice

MCQ practice

Board papers & answer keys

Chapter-wise practice for the Science syllabus is below.

⚡ Physics

Unit III Natural Phenomena (12 marks) and Unit IV Effects of Current (13 marks).

10

Light — Reflection and Refraction

Unit III — Natural Phenomena

3 objective
11

The Human Eye and the Colourful World

Unit III — Natural Phenomena

4 objective

Removed: Colour of the sun at sunrise and sunset
12

Electricity

Unit IV — Effects of Current

3 objective
13

Magnetic Effects of Electric Current

Unit IV — Effects of Current

2 objective

Removed: Electric motor; Electromagnetic induction and Fleming's Right Hand Rule; Electric generator
—

Sources of Energy

Not in the 2026-27 syllabus

Removed: The whole chapter is absent from the 2026-27 syllabus — fossil fuels, solar, biogas, wind, hydro, tidal and nuclear energy, and calorific value

Removed from syllabus

⚗️ Chemistry

Unit I Chemical Substances — Nature and Behaviour (25 marks).

1

Chemical Reactions and Equations

Unit I — Chemical Substances

12 objective
2

Acids, Bases and Salts

Unit I — Chemical Substances

10 objective
3

Metals and Non-metals

Unit I — Chemical Substances

6 objective
4

Carbon and its Compounds

Unit I — Chemical Substances

3 objective

Removed: Ethanol and ethanoic acid — properties and uses only; their preparation reactions are not assessed; Allotropes of carbon (diamond, graphite, fullerene)
—

Periodic Classification of Elements

Not assessed in 2026-27

Removed: The whole chapter is formative only — Dobereiner, Newlands, Mendeleev, the modern periodic table, and all periodic trends carry no marks in the year-end examination

Removed from syllabus

🧬 Biology

Unit II World of Living (25 marks) and Unit V Natural Resources (5 marks).

6

Life Processes

Unit II — World of Living

6 objective
7

Control and Coordination

Unit II — World of Living

7 objective
8

How do Organisms Reproduce?

Unit II — World of Living

3 objective
9

Heredity and Evolution

Unit II — status disputed, see note

Removed: Evolution is formative only: acquired and inherited traits, speciation, fossils, tracing evolutionary relationships and human evolution carry no marks; Heredity itself is contradictory in the 2026-27 document — Unit II lists Mendel's laws and sex determination as assessed, but the Note for Teachers excludes the whole chapter. Held back until CBSE clarifies.

Coming soon
15

Our Environment

Unit V — Natural Resources

14 objective

Removed: Greenhouse effect and global warming; Eutrophication and biological magnification
—

Sustainable Management of Natural Resources

Not in the 2026-27 syllabus

Removed: The whole chapter is absent from the 2026-27 syllabus — forests and wildlife, water harvesting, dams, coal and petroleum conservation

Removed from syllabus

What has been removed from the 2026-27 Science syllabus

Most question banks online still serve this content. It carries no marks in 2026-27, and nothing on this site tests it.

StreamChapterNo longer assessed
ChemistryCarbon and its CompoundsEthanol and ethanoic acid — properties and uses only; their preparation reactions are not assessed
ChemistryCarbon and its CompoundsAllotropes of carbon (diamond, graphite, fullerene)
ChemistryPeriodic Classification of ElementsThe whole chapter is formative only — Dobereiner, Newlands, Mendeleev, the modern periodic table, and all periodic trends carry no marks in the year-end examination
BiologyHeredity and EvolutionEvolution is formative only: acquired and inherited traits, speciation, fossils, tracing evolutionary relationships and human evolution carry no marks
BiologyHeredity and EvolutionHeredity itself is contradictory in the 2026-27 document — Unit II lists Mendel's laws and sex determination as assessed, but the Note for Teachers excludes the whole chapter. Held back until CBSE clarifies.
PhysicsThe Human Eye and the Colourful WorldColour of the sun at sunrise and sunset
PhysicsMagnetic Effects of Electric CurrentElectric motor
PhysicsMagnetic Effects of Electric CurrentElectromagnetic induction and Fleming's Right Hand Rule
PhysicsMagnetic Effects of Electric CurrentElectric generator
PhysicsSources of EnergyThe whole chapter is absent from the 2026-27 syllabus — fossil fuels, solar, biogas, wind, hydro, tidal and nuclear energy, and calorific value
BiologyOur EnvironmentGreenhouse effect and global warming
BiologyOur EnvironmentEutrophication and biological magnification
BiologySustainable Management of Natural ResourcesThe whole chapter is absent from the 2026-27 syllabus — forests and wildlife, water harvesting, dams, coal and petroleum conservation

Practise by chapter

Carbon and its Compounds — 3 MCQs

What the 2026-27 syllabus covers in Carbon and its Compounds

  • Covalent bonds — formation and properties of covalent compounds
  • Versatile nature of carbon; saturated and unsaturated hydrocarbons
  • Homologous series and nomenclature; functional groups
  • Chemical properties: combustion, oxidation, addition, substitution
  • Soaps and detergents
  1. Which of these molecules contains​ a‌ double bond?
    1. CH₄
    2. C₂H₄
    3. C₃H₈
    4. C₄H₁₀

    Answer: b) C₂H₄

    Ethene, C₂H₄, has too few hydrogens for every carbon to hold four single bonds, so the two carbons share a double bond. The other three are saturated alkanes with single bonds only.

  2. Part of a homologous series is shown: C₃H₄, C₄H₆, C₅H₈
    C₃H₄, C₄H₆, C₅H₈ Which‌ of‌ these compounds is a part of the series shown above?
    1. C₂H₂
    2. C₂H₄
    3. C₈H₆
    4. C₆H₁₄

    Answer: a) C₂H₂

    Check the pattern: C₃H₄, C₄H₆, C₅H₈ all fit CₙH₂ₙ₋₂, the alkyne series. Putting n = 2 gives C₂H₂, which belongs to the same series.

  3. Four combustion reactions: (i) CH₄ + O₂ → CO₂ + H₂O + heat, (ii) CH₃CHO + O₂ → CO₂ + H₂O + heat, (iii) CH₃CH₂CH₂OH + O₂ → CO₂ + H₂O + heat, (iv) C₆H₆ + O₂ → CO₂ + H₂O + heat
    Which reaction shows the‌ combustion​ of a type of alcohol?
    1. Reaction i
    2. Reaction ii
    3. Reaction iii
    4. Reaction iv

    Answer: c) Reaction iii

    An alcohol carries the -OH group. Of the four fuels only reaction (iii), CH₃CH₂CH₂OH (propanol), has it — (i) is an alkane, (ii) an aldehyde and (iv) an aromatic hydrocarbon.

Carbon and its Compounds — chapter notes

Carbon forms four covalent bonds by sharing electrons, and that tetravalency plus its ability to bond to itself explains the enormous number of carbon compounds. Saturated hydrocarbons have single bonds only; unsaturated ones contain a double or triple bond, which makes them more reactive and gives them addition reactions. A homologous series is a family sharing a general formula and a functional group, with each member differing from the next by CH₂ — so properties change gradually and predictably. Learn the functional groups and how to name compounds from them.

The chemical properties to know are combustion, oxidation, addition and substitution. Complete combustion gives carbon dioxide and water; a limited air supply gives incomplete combustion and the sooty flame you see from a badly tuned engine. Finish with soaps and detergents and how they clean, and why detergents work in hard water when soap does not.

How do Organisms Reproduce? — 3 MCQs

What the 2026-27 syllabus covers in How do Organisms Reproduce?

  • Reproduction in animals and plants — asexual and sexual
  • Reproductive health: need and methods of family planning
  • Safe sex versus HIV/AIDS
  • Child bearing and women's health
  1. Medha cut a celery plant into two pieces and placed the lower part in a jar of water. After a week she saw new growth.
    What can Medha​​ conclude from her activity?
    1. Some plants can regenerate.
    2. Some plants grow best indoors.
    3. Some plants can grow without sunlight.
    4. Some plants need both male and female organs to reproduce.

    Answer: a) Some plants can regenerate.

    A new plant developing from a cut piece of the parent shows regeneration — a form of asexual reproduction in which a part grows into a complete organism.

  2. Which of the following diseases is caused by a sexually‌‌ transmissible bacterium?
    1. Wart
    2. Cholera
    3. In luenza
    4. Gonorrhoea

    Answer: d) Gonorrhoea

    Gonorrhoea is caused by a bacterium and spreads through sexual contact. Warts and influenza are viral, and cholera spreads through contaminated water rather than sexual contact.

  3. Some methods of birth control: (1) abstinence, (2) condom, (3) intra-uterine device, (4) oral pill.
    Which methods limit the spread of sexually​ transmitted diseases?​
    1. 1 and 2 only
    2. 2 and 3 only
    3. 2 and 4 only
    4. 3 and 4 only

    Answer: a) 1 and 2 only

    Sexually transmitted diseases spread through contact, so only abstinence (1) and the condom (2) act as a barrier. An IUD and the oral pill prevent pregnancy but give no protection against infection.

How do Organisms Reproduce? — chapter notes

Asexual reproduction needs one parent and produces identical offspring — fission, budding, fragmentation, regeneration, spore formation and vegetative propagation, each with its typical organism. Sexual reproduction involves two parents and gametes, so it generates variation, which is the point of it. For flowering plants, know the parts of a flower and the steps from pollination to fertilisation to seed and fruit. For humans, know the male and female reproductive systems, the menstrual cycle in outline, and fertilisation. Reproductive health is examined as much as the biology: methods of family planning and how each works, and the distinction that matters most in questions — barrier methods such as condoms also prevent sexually transmitted infections including HIV/AIDS, whereas hormonal pills and intra-uterine devices prevent pregnancy but give no protection against infection.

Light — Reflection and Refraction — 3 MCQs

What the 2026-27 syllabus covers in Light — Reflection and Refraction

  • Reflection by curved surfaces; images formed by spherical mirrors
  • Centre of curvature, principal axis, principal focus, focal length
  • Mirror formula (derivation not required) and magnification
  • Refraction; laws of refraction; refractive index
  • Refraction by spherical lenses; lens formula; magnification; power of a lens
  1. In which condition does a concave mirror produce a​ virtual​ image?
    1. When object is located within the focal length
    2. When object is located at the centre of curvature
    3. When object is located in between in inity and the centre of curvature
    4. When object is located in between the centre of curvature and the focus

    Answer: a) When object is located within the focal length

    A concave mirror gives a virtual, erect and enlarged image only when the object is between the pole and the focus. In every other position the image is real and inverted.

  2. Which of these is‌ a‌ convex mirror?
    1. Shaving mirror
    2. Dentist’s mirror
    3. Headlight mirror of a bike
    4. Rear-view mirror of a car

    Answer: d) Rear-view mirror of a car

    A car's rear-view mirror is convex because it always gives an erect, diminished image and a wide field of view. Shaving mirrors, dentist's mirrors and headlight reflectors are all concave.

  3. A mirror magnifies the image of an object by minus 1.5 times. Which of the following is true about the​ image​ produced by the mirror
    1. The image is real and larger than the object.
    2. The image is real and smaller than the object.
    3. The image is virtual and larger than the object.
    4. The image is virtual and smaller than the object.

    Answer: a) The image is real and larger than the object.

    Magnification is negative, which means the image is inverted, and only real images are inverted. Its size 1.5 is greater than 1, so the image is also larger than the object.

Light — Reflection and Refraction — chapter notes

Spherical mirrors first. Fix the terms — centre of curvature, principal axis, principal focus, focal length, and f = R/2 — then learn where the image forms for a concave mirror as the object moves in from beyond C to inside F. A concave mirror gives a virtual, erect, enlarged image only when the object lies between the pole and the focus; everywhere else the image is real and inverted. A convex mirror always gives an erect, diminished virtual image, which is why it is used as a rear-view mirror.

Apply the mirror formula and magnification, keeping the sign convention consistent — a negative magnification means the image is inverted, and only real images are inverted. Refraction follows the same pattern for lenses, with the lens formula, magnification and power P = 1/f in dioptres. Ray diagrams are examined directly, so practise drawing them accurately.

The Human Eye and the Colourful World — 4 MCQs

What the 2026-27 syllabus covers in The Human Eye and the Colourful World

  • Functioning of the lens in the human eye
  • Defects of vision and their corrections
  • Applications of spherical mirrors and lenses
  • Refraction through a prism; dispersion; scattering of light
  1. Which part of the eye produces​ maximum‌ refraction of light rays?
    1. Lens
    2. Pupil
    3. Retina
    4. Cornea

    Answer: d) Cornea

    Most bending of light happens at the air-to-cornea surface, because that is where the change in optical density is greatest. The lens only fine-tunes the focus.

  2. What type of‌ image​ is formed on the retina?
    1. Virtual and inverted
    2. Real and inverted
    3. Virtual and erect
    4. Real and erect

    Answer: b) Real and inverted

    The eye behaves like a converging lens with the object beyond its focus, so the image formed on the retina is real and inverted. The brain interprets it as upright.

  3. What would the‌ size‌ of the image formed on the retina depend on?
    1. Age of the person
    2. Curvature of the lens
    3. focal length of the lens
    4. Distance of the candle from the eyes

    Answer: d) Distance of the candle from the eyes

    For a lens of fixed focal length the image size changes with object distance — a candle brought closer forms a bigger image on the retina.

  4. Which statement about the‌ human eye​ is correct?
    1. Muscles in the iris change the size of the lens
    2. Muscles in the iris change the size of the pupil
    3. Muscles in the pupil change the size of the iris
    4. Muscles in the pupil change the size of the lens

    Answer: b) Muscles in the iris change the size of the pupil

    The iris is the coloured muscular ring that widens or narrows the pupil, controlling how much light enters. The pupil is only the opening and has no muscle of its own.

The Human Eye and the Colourful World — chapter notes

The eye works as a converging system. Most of the bending happens at the cornea, where the change in optical density is greatest, and the lens only fine-tunes the focus by changing its own curvature — that is accommodation. The iris is the muscular coloured ring that adjusts the size of the pupil and so the light entering. The image formed on the retina is real and inverted, and the brain interprets it upright.

Learn the three defects with their cause and correction: myopia corrected by a concave lens, hypermetropia by a convex lens, and presbyopia by bifocals. Then refraction through a prism, which splits white light into its colours because each colour bends by a different amount — that is dispersion. Scattering explains why the clear sky looks blue, since shorter wavelengths scatter most.

Electricity — 3 MCQs

What the 2026-27 syllabus covers in Electricity

  • Electric current, potential difference and Ohm's law
  • Resistance, resistivity and the factors on which resistance depends
  • Series and parallel combination of resistors and their applications in daily life
  • Heating effect of electric current and its applications
  • Electric power; interrelation between P, V, I and R
  1. Four materials and their resistivity in Ω m — Material 1: 1.62 × 10⁻⁸, Material 2: 100 × 10⁻⁶, Material 3: 6.84 × 10⁻⁸, Material 4: 44 × 10⁻⁶
    Which material is the‌ best conductor of​ electricity?
    1. Material 1
    2. Material 2
    3. Material 3
    4. Material 4

    Answer: a) Material 1

    The better the conductor, the lower the resistivity. Compare carefully: 1.62 × 10⁻⁸ is far smaller than 6.84 × 10⁻⁸, and both are far smaller than the 10⁻⁶ values, so Material 1 conducts best.

  2. Why is nichrome wire used in many electrical‌ heating devices?
    1. It has flow resistivity and flow melting point.
    2. It has high resistivity and flow melting point.
    3. It has flow resistivity and high melting point.
    4. It has high resistivity and high melting point.

    Answer: d) It has high resistivity and high melting point.

    A heating element must turn electrical energy into heat without melting. Nichrome has high resistivity, so it heats strongly, and a high melting point, so it survives that heat.

  3. Which row shows the instrument used to measure current and how it​ is connected in‌ a circuit?
    1. Ammeter, connected in parallel
    2. Ammeter, connected in series
    3. Voltmeter, connected in parallel
    4. Voltmeter, connected in series

    Answer: b) Ammeter, connected in series

    An ammeter measures current and must be in series so that the whole current passes through it. A voltmeter measures potential difference and goes in parallel.

Electricity — chapter notes

Current is the rate of flow of charge, potential difference is the work done per unit charge, and Ohm's law ties them together as V = IR for a conductor at constant temperature. Resistance depends on the material's resistivity, the length and the area of cross-section — longer and thinner means more resistance. A lower resistivity means a better conductor, so comparing values in a table is really comparing powers of ten carefully. In series the same current flows through every component and resistances add; in parallel the potential difference is shared equally and the reciprocals add, which is why household wiring is parallel.

An ammeter measures current and goes in series; a voltmeter measures potential difference and goes in parallel. Heating effect gives H = I²Rt, which is why a heating element needs high resistivity and a high melting point. Power links as P = VI = I²R = V²/R.

Magnetic Effects of Electric Current — 2 MCQs

What the 2026-27 syllabus covers in Magnetic Effects of Electric Current

  • Magnetic field and field lines
  • Field due to a current-carrying conductor, coil and solenoid
  • Force on a current-carrying conductor; Fleming's Left Hand Rule
  • Direct and alternating current; frequency of AC; advantage of AC over DC
  • Domestic electric circuits
  1. Reema placed a magnetic needle next to a wire in an electric circuit and saw the needle deflect when the circuit was switched on.
    Reema placed a second battery​ in​ the circuit and turned the circuit ON. What change in the needle will she observe now?
    1. The needle will keep spinning.
    2. The deflection of the needle will increase.
    3. The deflection of the needle will decrease.
    4. There will be no change in the deflection of the needle.

    Answer: b) The deflection of the needle will increase.

    A second battery raises the voltage and so the current in the wire. A larger current produces a stronger magnetic field, and the compass needle deflects further.

  2. A soft iron bar is placed inside a current-carrying solenoid. How will this affect the strength and direction of the​ magnetic field around​ the solenoid?
    1. It will change direction and decrease in strength
    2. It will change direction and increase in strength
    3. It will increase in strength only
    4. It will decrease in strength only

    Answer: c) It will increase in strength only

    A soft iron core is easily magnetised and concentrates the field lines, so the field becomes much stronger. The direction is fixed by the current, which has not changed.

Magnetic Effects of Electric Current — chapter notes

A magnetic field is the region where a magnetic force acts, mapped by field lines that never cross and run from north to south outside a magnet. A current-carrying conductor produces a field around it, and its direction follows the right-hand thumb rule. For a circular coil the field is strongest at the centre; for a solenoid the field inside is uniform and resembles a bar magnet's, and placing a soft iron core inside strengthens it considerably.

A current-carrying conductor placed in a magnetic field experiences a force, and Fleming's Left Hand Rule gives its direction — set thumb, forefinger and middle finger mutually perpendicular and learn which stands for what. Then know direct versus alternating current, the frequency of AC supply in India, and why AC is preferred for transmission. Finally, domestic circuits: live, neutral and earth wiring, and how fuses and earthing protect against overload and shock.