Class 10 Science MCQs for Exams

Class 10 Science includes all the important scientific concepts: from laws of motion to electricity, organic chemistry, and human biology. This series of MCQs is prepared to help students in achieving their goal of making themselves perfect for board exams and to give a clear review of all the important concepts coming under the major scientific disciplines. Let’s see how well you know your Class 10 Science topics.

1. What is the SI unit of force?

  • A) Joule
  • B) Newton
  • C) Watt
  • D) Pascal

Answer: B) Newton
The SI unit of force is the Newton (N), named after Sir Isaac Newton.


2. Which of the following is a vector quantity?

  • A) Speed
  • B) Mass
  • C) Force
  • D) Distance

Answer: C) Force
Force is a vector quantity because it has both magnitude and direction.


3. What is the chemical formula for calcium carbonate?

  • A) CaCO3
  • B) CaCl2
  • C) CaSO4
  • D) CaO

Answer: A) CaCO3
Calcium carbonate is commonly found in limestone, chalk, and marble, and its formula is CaCO3.


4. The pH value of a neutral solution is:

  • A) 0
  • B) 7
  • C) 14
  • D) 1

Answer: B) 7
The pH value of a neutral solution, such as pure water, is 7, meaning it is neither acidic nor basic.


5. Which gas is produced when an acid reacts with a metal?

  • A) Oxygen
  • B) Nitrogen
  • C) Hydrogen
  • D) Carbon dioxide

Answer: C) Hydrogen
When an acid reacts with a metal, hydrogen gas is produced, as seen in the reaction between hydrochloric acid and zinc.


6. What is the SI unit of electric current?

  • A) Volt
  • B) Ampere
  • C) Watt
  • D) Ohm

Answer: B) Ampere
The SI unit of electric current is the Ampere (A).


7. Which of the following is an example of a physical change?

  • A) Burning of wood
  • B) Rusting of iron
  • C) Melting of wax
  • D) Digestion of food

Answer: C) Melting of wax
Melting of wax is a physical change because the substance changes state but remains the same chemically.


8. Which of the following is not an example of a renewable resource?

  • A) Solar energy
  • B) Wind energy
  • C) Coal
  • D) Biomass

Answer: C) Coal
Coal is a non-renewable resource, whereas solar energy, wind energy, and biomass are renewable resources.


9. What is the function of the xylem in plants?

  • A) Transport of water
  • B) Transport of food
  • C) Photosynthesis
  • D) Storage of food

Answer: A) Transport of water
Xylem transports water and minerals from the roots to other parts of the plant.


10. The law of reflection states that:

  • A) Angle of incidence = Angle of reflection
  • B) Angle of incidence = Angle of refraction
  • C) Angle of reflection = 90°
  • D) Light bends when it passes through different mediums

Answer: A) Angle of incidence = Angle of reflection
The law of reflection states that the angle of incidence is equal to the angle of reflection.


11. Which of the following is a chemical property of acids?

  • A) They taste sour
  • B) They turn blue litmus paper red
  • C) They react with metals to release hydrogen
  • D) All of the above

Answer: D) All of the above
Acids have several properties, including sour taste, turning blue litmus paper red, and reacting with metals to release hydrogen gas.


12. What is the primary source of energy for all living organisms?

  • A) Sunlight
  • B) Oxygen
  • C) Water
  • D) Soil

Answer: A) Sunlight
Sunlight is the primary energy source for photosynthetic organisms, which form the base of most food chains.


13. Which of the following is a non-renewable resource?

  • A) Wind energy
  • B) Hydroelectric power
  • C) Coal
  • D) Solar energy

Answer: C) Coal
Coal is a fossil fuel and a non-renewable resource, as it cannot be replenished in a short time.


14. Which of the following is a unit of work?

  • A) Ampere
  • B) Joule
  • C) Watt
  • D) Newton

Answer: B) Joule
The unit of work is the Joule (J), which is equal to one Newton meter.


15. Which of the following is responsible for the green color of leaves?

  • A) Carotene
  • B) Chlorophyll
  • C) Xanthophyll
  • D) Melanin

Answer: B) Chlorophyll
Chlorophyll is the pigment responsible for the green color in plants and plays a key role in photosynthesis.


16. Which of the following is an example of a heterogeneous mixture?

  • A) Salt solution
  • B) Air
  • C) Oil and water
  • D) Vinegar

Answer: C) Oil and water
Oil and water do not mix and form a heterogeneous mixture, meaning the components are not uniformly distributed.


17. What is the function of the human respiratory system?

  • A) To digest food
  • B) To circulate blood
  • C) To exchange gases between the body and the environment
  • D) To regulate body temperature

Answer: C) To exchange gases between the body and the environment
The respiratory system is responsible for taking in oxygen and expelling carbon dioxide from the body.


18. What is the main purpose of the heart in the human circulatory system?

  • A) To pump oxygenated blood to the body
  • B) To produce blood cells
  • C) To transport nutrients
  • D) To filter waste from the blood

Answer: A) To pump oxygenated blood to the body
The heart pumps oxygenated blood to all parts of the body, ensuring tissues receive the oxygen they need.


19. Which of the following is a property of acids?

  • A) They taste bitter
  • B) They turn red litmus paper blue
  • C) They taste sour
  • D) They are slippery to touch

Answer: C) They taste sour
Acids have a sour taste, which is why lemon juice and vinegar are sour.


20. What is the term for a solution with a pH less than 7?

  • A) Neutral
  • B) Acidic
  • C) Basic
  • D) Alkaline

Answer: B) Acidic
A solution with a pH less than 7 is acidic, indicating the presence of more hydrogen ions.


21. Which of the following is a unit of frequency?

  • A) Hertz
  • B) Newton
  • C) Joule
  • D) Watt

Answer: A) Hertz
The unit of frequency is Hertz (Hz), which represents the number of cycles per second.


22. Which of the following elements is most commonly found in all living organisms?

  • A) Iron
  • B) Oxygen
  • C) Carbon
  • D) Nitrogen

Answer: C) Carbon
Carbon is the most essential element in all living organisms as it forms the backbone of organic molecules.


23. What happens to the rate of reaction when temperature increases?

  • A) It decreases
  • B) It remains the same
  • C) It increases
  • D) It becomes zero

Answer: C) It increases
Increasing the temperature usually speeds up chemical reactions by providing more energy to the reacting molecules.


24. What is the main cause of acid rain?

  • A) Carbon dioxide
  • B) Nitrogen oxide and sulfur dioxide
  • C) Oxygen
  • D) Methane

Answer: B) Nitrogen oxide and sulfur dioxide
Acid rain is caused by the presence of nitrogen oxides and sulfur dioxide in the atmosphere, which combine with water vapor to form acids.


25. Which of the following is an example of a renewable source of energy?

  • A) Coal
  • B) Wind
  • C) Natural gas
  • D) Oil

Answer: B) Wind
Wind energy is renewable, as it is naturally replenished and does not get depleted by use.


26. What is the formula for calculating work done?

  • A) Work = Force × Distance
  • B) Work = Mass × Acceleration
  • C) Work = Energy × Time
  • D) Work = Speed × Time

Answer: A) Work = Force × Distance
Work is calculated by multiplying force applied by the distance over which it is applied.


27. Which of the following is the SI unit of energy?

  • A) Watt
  • B) Joule
  • C) Newton
  • D) Ampere

Answer: B) Joule
The SI unit of energy is the Joule (J).


28. Which part of the cell controls its activities?

  • A) Mitochondria
  • B) Nucleus
  • C) Cytoplasm
  • D) Ribosomes

Answer: B) Nucleus
The nucleus controls all activities of the cell, including growth, reproduction, and metabolism.


29. Which of the following is a characteristic of a convex lens?

  • A) It diverges light
  • B) It magnifies objects
  • C) It forms only real images
  • D) It focuses light to a point

Answer: B) It magnifies objects
A convex lens magnifies objects by converging light rays to a focal point.


30. Which of the following metals is extracted from bauxite?

  • A) Iron
  • B) Copper
  • C) Aluminum
  • D) Zinc

Answer: C) Aluminum
Aluminum is extracted from bauxite ore through the Bayer process.

31. What is the term for the change of state from a gas to a liquid?

  • A) Condensation
  • B) Evaporation
  • C) Melting
  • D) Freezing

Answer: A) Condensation
Condensation is the process by which a gas turns into a liquid when it cools down.


32. Which of the following best describes the function of a diaphragm in the human respiratory system?

  • A) It increases the size of the lungs
  • B) It separates the lungs from the heart
  • C) It helps in the expansion and contraction of the lungs
  • D) It filters harmful particles from the air

Answer: C) It helps in the expansion and contraction of the lungs
The diaphragm is a muscle that contracts and expands to help in the inhalation and exhalation of air.


33. Which of the following is a property of metals?

  • A) Non-conductive
  • B) Brittle
  • C) Malleable
  • D) Transparent

Answer: C) Malleable
Metals are malleable, meaning they can be hammered or pressed into thin sheets without breaking.


34. What type of chemical bond is formed when electrons are shared between two atoms?

  • A) Ionic bond
  • B) Covalent bond
  • C) Hydrogen bond
  • D) Metallic bond

Answer: B) Covalent bond
A covalent bond is formed when two atoms share electrons to achieve a stable electron configuration.


35. What is the atomic number of carbon?

  • A) 6
  • B) 8
  • C) 12
  • D) 14

Answer: A) 6
Carbon has an atomic number of 6, which means it has 6 protons in its nucleus.


36. What is the main role of the chloroplast in plant cells?

  • A) Energy production
  • B) Photosynthesis
  • C) Protein synthesis
  • D) Cellular respiration

Answer: B) Photosynthesis
Chloroplasts are responsible for photosynthesis, where sunlight is used to make food for the plant.


37. Which of the following is a unit of pressure?

  • A) Newton
  • B) Watt
  • C) Pascal
  • D) Joule

Answer: C) Pascal
The SI unit of pressure is the Pascal (Pa), which is defined as one newton per square meter.


38. Which of the following best describes the process of transpiration in plants?

  • A) Movement of water from the roots to leaves
  • B) Movement of water through the soil
  • C) Evaporation of water from plant leaves
  • D) Absorption of nutrients from the soil

Answer: C) Evaporation of water from plant leaves
Transpiration is the process where water evaporates from the plant’s leaves into the atmosphere.


39. What is the function of the kidneys in humans?

  • A) To filter waste from the blood and produce urine
  • B) To regulate body temperature
  • C) To circulate blood
  • D) To help with digestion

Answer: A) To filter waste from the blood and produce urine
The kidneys filter waste and excess substances from the blood, producing urine for excretion.


40. What is the result of the neutralization reaction between an acid and a base?

  • A) Water and salt
  • B) Oxygen and water
  • C) Carbon dioxide and water
  • D) Hydrogen and oxygen

Answer: A) Water and salt
When an acid reacts with a base, it produces water and a salt as the products of the neutralization reaction.


41. Which of the following is the main component of natural gas?

  • A) Methane
  • B) Ethanol
  • C) Hydrogen
  • D) Butane

Answer: A) Methane
Methane (CH₄) is the main component of natural gas and is used primarily as a fuel source.


42. What is the relationship between current, voltage, and resistance in an electric circuit?

  • A) Ohm’s Law
  • B) Newton’s Law
  • C) Boyle’s Law
  • D) Bernoulli’s Principle

Answer: A) Ohm’s Law
Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage and inversely proportional to the resistance.


43. What is the energy transformation when a battery is used to power a flashlight?

  • A) Chemical energy to mechanical energy
  • B) Chemical energy to light energy
  • C) Chemical energy to thermal energy
  • D) Electrical energy to light energy

Answer: B) Chemical energy to light energy
In a flashlight, chemical energy stored in the battery is converted into light energy.


44. What is the cause of tides on Earth?

  • A) The Moon’s gravitational pull
  • B) Earth’s rotation
  • C) Solar radiation
  • D) Wind patterns

Answer: A) The Moon’s gravitational pull
Tides are caused by the gravitational pull of the Moon and, to a lesser extent, the Sun on Earth’s oceans.


45. Which of the following is an example of a decomposer in an ecosystem?

  • A) Grasshopper
  • B) Lion
  • C) Mushroom
  • D) Frog

Answer: C) Mushroom
Mushrooms are decomposers that break down dead organic matter, returning nutrients to the soil.


46. The process in which a solid turns directly into a gas is called:

  • A) Sublimation
  • B) Evaporation
  • C) Melting
  • D) Freezing

Answer: A) Sublimation
Sublimation is the process in which a solid turns directly into a gas without passing through the liquid state.


47. What is the function of the digestive system in humans?

  • A) To circulate blood
  • B) To break down food into nutrients for absorption
  • C) To transport oxygen to the body
  • D) To eliminate waste products

Answer: B) To break down food into nutrients for absorption
The digestive system breaks down food into simpler molecules that can be absorbed by the body.


48. Which of the following is an example of a physical change?

  • A) Burning of paper
  • B) Rusting of iron
  • C) Dissolving salt in water
  • D) Digestion of food

Answer: C) Dissolving salt in water
Dissolving salt in water is a physical change, as the salt remains the same substance, even though it dissolves.


49. What happens when an electric current passes through a conductor?

  • A) Heat is generated
  • B) The conductor gets colder
  • C) It breaks the conductor
  • D) Light is emitted

Answer: A) Heat is generated
When electric current passes through a conductor, resistance causes the conductor to heat up, which is the principle behind electric heating.


50. Which of the following is a non-metal used in the manufacturing of fertilizers?

  • A) Nitrogen
  • B) Iron
  • C) Copper
  • D) Calcium

Answer: A) Nitrogen
Nitrogen is a non-metal commonly used in the production of fertilizers as it is essential for plant growth.


This concludes the set of 50 MCQs for Class 10 Science, which provides an extensive overview of the topics covered in your curriculum. Review these questions to reinforce your understanding and prepare well for your exams.

Also Read: Everyday Science MCQs: Important for Examination

You may also like to Read: 50 MCQs on the Economy of India for Exams

Leave a Comment