The CBSE Class 10 Science exam carries significant marks for Multiple Choice Questions (MCQs), contributing around 20 marks to the total exam score. These MCQs are designed to test students' conceptual understanding across Physics, Chemistry, and Biology chapters. To support students preparing for their Half Yearly Exam 2025-26, we have carefully compiled a list of the top 50 Science MCQs that reflect important topics and trends from previous years. These questions are designed based on the latest CBSE exam pattern and provide an effective resource for last-minute revision.
Also check: CBSE Class 10 Science Syllabus 2025-26: Free PDF Download
Why Focus on Science MCQs?
- Covers key chapters from Physics, Chemistry, and Biology of Class 10 syllabus.
- Designed in line with the latest CBSE exam pattern for 2025-26.
- Curated by subject experts after thorough analysis of past exam papers.
- Helps students boost speed, accuracy, and conceptual clarity.
- Ideal for last-minute preparation and self-assessment.
Top 50 MCQs for CBSE Class 10 Science Half Yearly Exam 2025-26
- The metals obtained from their molten chlorides by electrolytic reduction are:
a) Gold and Silver
b) Calcium and Magnesium
c) Aluminium and Silver
d) Sodium and Iron - The formation of Magnesium Oxide is correctly shown by:
A) Mg → loses 2e⁻, O → gains 2e⁻ - When element A loses electrons and element B gains electrons to form compound C, which property will C NOT show?
a) High melting point
b) Highly soluble in water
c) Strong electrostatic force between ions
d) Conducts electricity in solid state - Which products are formed when Aluminium and Magnesium burn in air?
a) Al₃O₄ and MgO₂
b) Al₂O₃ and MgO
c) Al₃O₄ and MgO
d) Al₂O₃ and MgO₂ - During electrolysis of water, the ratio of masses of hydrogen to oxygen liberated (MH : MO) is –
a) 8 : 1
b) 2 : 1
c) 1 : 2
d) 1 : 8 - The breakdown of glucose takes place in cytoplasm and then in absence of oxygen in muscles it forms –
a) Alcohol
b) Acetic acid
c) Lactic acid
d) Citric acid - If pea plants with round green seeds (RRyy) are crossed with wrinkled yellow seeds (rrYY), the F1 generation will produce –
a) 50% round and green
b) 75% wrinkled and green
c) 100% round and yellow
d) 75% wrinkled and yellow - The plant hormone which promotes cell elongation on the shady side of a shoot is –
a) Cytokinin
b) Gibberellin
c) Auxin
d) Adrenaline - Tooth enamel (Ca-hydroxyapatite) starts corroding in the mouth when the pH is –
a) 7
b) 5
c) 10
d) 14 - In a terrestrial ecosystem, the percentage of solar energy not converted into food energy is about –
a) 1%
b) 10%
c) 90%
d) 99% - The visibility of smoke particles in a dark room when a beam of sunlight enters through a hole is due to –
a) Dispersion of light
b) Reflection of light
c) Internal reflection
d) Scattering of light - Mirror X is used in solar furnace and Mirror Y as a rear-view mirror. Which is correct?
a) X forms real, diminished image at focus and Y forms virtual, diminished erect image
b) X forms virtual, diminished image and Y forms real, diminished image
c) Both X and Y form virtual images
d) Both X and Y form real images - Assertion (A): Ozone levels dropped sharply after 1980.
Reason (R): O atoms combine with O₂ to form ozone.
a) Both A and R true, R explains A
b) Both A and R true, R not explanation
c) A true, R false
d) A false, R true - Assertion (A): No two magnetic field lines cross each other.
Reason (R): A compass cannot point in two directions simultaneously.
a) Both A and R true, R explains A
b) Both A and R true, R not explanation
c) A true, R false
d) A false, R true - Assertion (A): Human child bears all basic features of human beings.
Reason (R): It looks exactly like its parents.
a) Both A and R true, R explains A
b) Both A and R true, R not explanation
c) A true, R false
d) A false, R true - Assertion (A): Decomposition reactions are generally endothermic.
Reason (R): Decomposition of organic matter into compost is exothermic.
a) Both A and R true, R explains A
b) Both A and R true, R not explanation
c) A true, R false
d) A false, R true - A current of 1 A is drawn by a filament bulb. The number of electrons passing per second is –
a) 7 × 10¹⁸
b) 5 × 10¹⁸
c) 1 × 10¹⁹
d) 14 × 10¹⁸ - Which law is obeyed in the reflection of light from a plane mirror?
a) Snell’s Law
b) Ohm’s Law
c) Law of Reflection
d) Faraday’s Law - Image formed by a concave mirror when the object is beyond 2F is –
a) Virtual, erect, magnified
b) Real, inverted, diminished
c) Real, inverted, magnified
d) Virtual, diminished - The colour of the sky appears blue because of –
a) Reflection of sunlight
b) Dispersion of light
c) Scattering of light
d) Refraction of light - Which group does NOT represent a food chain?
a) Wolf → Rabbit → Grass → Lion
b) Plankton → Man → Grasshopper → Fish
c) Hawk → Grass → Snake → Frog
d) Grass → Snake → Wolf → Tiger - The secretion of less saliva in the mouth will affect the conversion of –
a) Proteins → Amino acids
b) Fats → Fatty acids & Glycerol
c) Starch → Simple sugars
d) Sugars → Alcohol - Which phenomenon makes sunlight beam visible in a smoke-filled room?
a) Dispersion
b) Reflection
c) Internal reflection
d) Scattering - The hormone secreted during fear or emergency situation is –
a) Auxin
b) Adrenaline
c) Cytokinin
d) Gibberellin - Which statement about bisexual flowers is correct?
a) They cannot produce fruits
b) They have both stamen & pistil
c) They only undergo cross-pollination
d) They only undergo self-pollination - Which image is always virtual, erect and diminished?
a) Concave lens
b) Convex lens
c) Concave mirror
d) Plane mirror - A mild non-corrosive basic salt used for faster cooking is –
a) Sodium carbonate
b) Baking soda (NaHCO₃)
c) Washing soda
d) Common salt - The products obtained during electrolysis of brine are –
a) H₂, O₂, NaOH
b) H₂, Cl₂, NaOH
c) H₂, Cl₂, HCl
d) Na, O₂, Cl₂ - Which law states that incident ray, reflected ray and normal lie in the same plane?
a) Snell’s Law
b) Second Law of Reflection
c) Faraday’s Law
d) Joule’s Law - In a human female reproductive system, the function of fallopian tube is –
a) Nourishes embryo
b) Site of fertilisation
c) Produces eggs
d) Provides birth canal - A prism ABC (with BC as base) is placed in different orientations. A narrow beam of white light is incident on the prism as shown in figure. In which of the following cases, after dispersion, the third colour from the top corresponds to the colour of the sky?
a) (a)
b) (b)
c) (c)
d) (d) - Two heater wires of equal length are first connected in series and then in parallel with a battery. The ratio of heat produced in the two cases is:
a) 2 : 1
b) 1 : 2
c) 4 : 1
d) 1 : 4 - An electron beam enters a magnetic field at right angles to it as shown in the figure.
a) To the left
b) To the right
c) Into the page
d) Out of the page - A beam of light is incident through the holes on side A and emerges out of the holes on the other side B as shown in the figure below:
a) Concave lens
b) Rectangular glass slab
c) Prism
d) Convex lens - The refractive index of flint glass is 1.65 and that for alcohol is 1.36 with respect to air. What is the refractive index of the flint glass with respect to alcohol?
a) 0.82
b) 1.21
c) 1.11
d) 1.01 - The least distance of distinct vision for a young adult with normal vision is about:
a) 25 m
b) 2.5 cm
c) 25 cm
d) 2.5 m - The slope of voltage (V) versus current (I) is called:
a) Resistance
b) Conductance
c) Resistivity
d) Conductivity - Inside the magnet, the field lines move—
a) From north to south
b) From south to north
c) Away from south pole
d) Away from north pole - Every food chain in the ecosystem begins with ……… which is the original source of food.
a) Saprophytes
b) Parasites
c) Producers
d) Consumers - The image shows the bread moulds on a bread. How do these fungi obtain nutrition?
a) By eating the bread on which it is growing
b) By using nutrients from the bread to prepare their own food
c) By breaking down the nutrients of bread and then absorbing them
d) By allowing other organisms to grow on the bread and then consuming them - The brain is responsible for:
a) Thinking
b) Regulating the heart beat
c) Balancing the body
d) All of the above - In the figure, the parts A, B and C are sequentially:
a) Cotyledon, plumule and radicle
b) Plumule, radicle and cotyledon
c) Plumule, cotyledon and radicle
d) Radicle, cotyledon and plumule - Identify the totally impossible outcome of Mendel’s Experiment (cross breeding pure bred tall and short pea plants):
a) 3 tall 1 short plant
b) 24 tall and 8 short plants
c) 8 tall and 0 short plants
d) 4 tall plants and 1 medium-height plant - The longest fiber on the cell body of a neuron is called:
a) Sheath
b) Cytoplasm
c) Axon
d) Dendrites - Vegetative propagation refers to formation of new plants from:
a) Stem, flowers and fruits
b) Stem, leaves and flowers
c) Stem, roots and flowers
d) Stem, roots and leaves - A section of DNA providing information for one protein is called—
a) Nucleus
b) Chromosomes
c) Trait
d) Gene - The nature of image formed by a convex mirror when the object distance from the mirror is less than the distance between pole and focal point (F) of the mirror would be:
a) Real, inverted, diminished
b) Real, inverted, enlarged
c) Virtual, upright, diminished
d) Virtual, upright, enlarged - If a man’s face is 25 cm in front of concave shaving mirror producing erect image 1.5 times the size of face, focal length of the mirror would be:
a) 75 cm
b) 25 cm
c) 15 cm
d) 60 cm - A couple has two sons and three daughters. What is the possibility of their having a girl as sixth child?
a) 10 %
b) 50 %
c) 90 %
d) 100 % - What is the order of the waste management hierarchy, from most to least favored?
a) Prevention–Recycle–Reuse–Disposal
b) Prevention–Reuse–Disposal–Recycle
c) Prevention–Disposal–Reuse–Recycle
d) Prevention–Reuse–Recycle–Disposal
This comprehensive list of top 50 MCQs covers all the crucial chapters of CBSE Class 10 Science and is highly recommended for students aiming to maximize their performance in the Half Yearly Exam 2025-26.
