📘 Chapter 1 – The Ever-Evolving World of Science

Part 2: MCQs (Q26–Q50)

Sub-Topics: Introduction to Science, Science in Everyday Life

Q26. Which everyday activity shows Newton’s third law of motion?

A) Walking on the ground
B) Lighting a candle
C) Making tea
D) Sleeping

✅ Correct Answer: A) Walking on the ground

Explanation:

• A) Walking on the ground – Correct, we push the ground backward, the ground pushes us forward (action–reaction).
• B) Lighting a candle – Involves combustion, not Newton’s law.
• C) Making tea – More of a chemistry process.
• D) Sleeping – No connection to Newton’s third law.

Q27. Which of these scientific inventions helps in measuring temperature?

A) Microscope
B) Thermometer
C) Barometer
D) Telescope

✅ Correct Answer: B) Thermometer

Explanation:

• A) Microscope – Used for small objects, not temperature.
• B) Thermometer – Correct, measures hotness or coldness.
• C) Barometer – Measures atmospheric pressure.
• D) Telescope – For celestial bodies.

Q28. Which branch of science studies earthquakes?

A) Geology
B) Zoology
C) Botany
D) Astronomy

✅ Correct Answer: A) Geology

Explanation:

• A) Geology – Correct, studies Earth, rocks, earthquakes.
• B) Zoology – Study of animals.
• C) Botany – Study of plants.
• D) Astronomy – Study of space.

Q29. Which simple machine is used in a see-saw?

A) Pulley
B) Wedge
C) Lever
D) Screw

✅ Correct Answer: C) Lever

Explanation:

• A) Pulley – Used to lift weights, not see-saw.
• B) Wedge – Used for cutting, not see-saw.
• C) Lever – Correct, see-saw is a lever with fulcrum in middle.
• D) Screw – Used in fastening.

Q30. Who discovered penicillin, the first antibiotic?

A) Alexander Fleming
B) Louis Pasteur
C) Edward Jenner
D) Robert Koch

✅ Correct Answer: A) Alexander Fleming

Explanation:

• A) Fleming – Correct, discovered penicillin in 1928.
• B) Pasteur – Developed vaccines, germ theory.
• C) Jenner – Invented smallpox vaccine.
• D) Koch – Worked on disease-causing microbes.

Q31. Which of these is a disadvantage of science?

A) Faster transport
B) Pollution of environment
C) Development of medicines
D) Better communication

✅ Correct Answer: B) Pollution of environment

Explanation:

• A) Faster transport – Advantage.
• B) Pollution – Correct, side effect of industrialization.
• C) Medicines – Positive impact.
• D) Communication – Benefit of science.

Q32. The process of photosynthesis is mainly studied in which branch of science?

A) Physics
B) Chemistry
C) Botany
D) Zoology

✅ Correct Answer: C) Botany

Explanation:

• A) Physics – Not related.
• B) Chemistry – Involves chemical changes, but studied mainly in biology.
• C) Botany – Correct, study of plants, including photosynthesis.
• D) Zoology – Study of animals.

Q33. Which of the following is NOT an invention of science?

A) Electric bulb
B) Aeroplane
C) Rainfall
D) Computer

✅ Correct Answer: C) Rainfall

Explanation:

• A) Electric bulb – Invention.
• B) Aeroplane – Invention.
• C) Rainfall – Correct, natural process, not invented.
• D) Computer – Invention.

Q34. Which type of energy is obtained from moving water?

A) Nuclear energy
B) Hydroelectric energy
C) Geothermal energy
D) Solar energy

✅ Correct Answer: B) Hydroelectric energy

Explanation:

• A) Nuclear – From atomic reactions.
• B) Hydroelectric – Correct, moving water turns turbines to generate electricity.
• C) Geothermal – From Earth’s heat.
• D) Solar – From sunlight.

Q35. Which scientist discovered that plants release oxygen?

A) Joseph Priestley
B) Robert Hooke
C) Charles Darwin
D) Isaac Newton

✅ Correct Answer: A) Joseph Priestley

Explanation:

• A) Priestley – Correct, showed plants release oxygen during photosynthesis.
• B) Hooke – Discovered cells.
• C) Darwin – Theory of evolution.
• D) Newton – Law of gravity.

Q36. Which of these is an example of physical change?

A) Rusting of iron
B) Burning of paper
C) Melting of ice
D) Cooking of rice

✅ Correct Answer: C) Melting of ice

Explanation:

• A) Rusting – Chemical change.
• B) Burning – Chemical change.
• C) Melting ice – Correct, only change of state.
• D) Cooking rice – Chemical change.

Q37. Which device is based on reflection of sound waves?

A) Microscope
B) Stethoscope
C) Sonar
D) Periscope

✅ Correct Answer: C) Sonar

Explanation:

• A) Microscope – Light, not sound.
• B) Stethoscope – Sound conduction, not reflection.
• C) Sonar – Correct, uses sound reflection to detect underwater objects.
• D) Periscope – Reflection of light, not sound.

Q38. Which scientific instrument is used to measure atmospheric pressure?

A) Thermometer
B) Barometer
C) Hygrometer
D) Speedometer

✅ Correct Answer: B) Barometer

Explanation:

• A) Thermometer – Measures temperature.
• B) Barometer – Correct, measures pressure.
• C) Hygrometer – Measures humidity.
• D) Speedometer – Measures speed.

Q39. Which of these is NOT a renewable resource?

A) Sunlight
B) Wind
C) Coal
D) Water

✅ Correct Answer: C) Coal

Explanation:

• A) Sunlight – Renewable.
• B) Wind – Renewable.
• C) Coal – Correct, non-renewable fossil fuel.
• D) Water – Renewable (if conserved).

Q40. Which of these shows use of science in agriculture?

A) Tractors
B) Fertilizers
C) Irrigation pumps
D) All of the above

✅ Correct Answer: D) All of the above

Explanation:

• A) Tractors – Machines for farming.
• B) Fertilizers – Chemical science.
• C) Irrigation – Scientific water use.
• D) All – Correct, all are applications in agriculture.

Q41. Which Indian scientist won the Nobel Prize for Physics in 1930?

A) Homi J. Bhabha
B) C.V. Raman
C) A.P.J. Abdul Kalam
D) S. Chandrasekhar

✅ Correct Answer: B) C.V. Raman

Explanation:

• A) Bhabha – Nuclear physics.
• B) Raman – Correct, Nobel Prize for Raman Effect.
• C) Kalam – Missile scientist, not Nobel laureate.
• D) Chandrasekhar – Won Nobel later (1983).

Q42. Which of the following is NOT a use of electricity?

A) Lighting
B) Heating
C) Cooling
D) Photosynthesis

✅ Correct Answer: D) Photosynthesis

Explanation:

• A) Lighting – Uses electricity.
• B) Heating – Uses electricity.
• C) Cooling – Fans, ACs use electricity.
• D) Photosynthesis – Correct, uses sunlight, not electricity.

Q43. Which type of energy does a moving car possess?

A) Potential energy
B) Kinetic energy
C) Nuclear energy
D) Chemical energy

✅ Correct Answer: B) Kinetic energy

Explanation:

• A) Potential – Stored energy.
• B) Kinetic – Correct, energy of motion.
• C) Nuclear – Atomic reactions.
• D) Chemical – Stored in fuel, but motion shows kinetic.

Q44. Which of these is NOT an example of biotechnology?

A) Making cheese
B) Preparing antibiotics
C) Using internet
D) Fermentation of wine

✅ Correct Answer: C) Using internet

Explanation:

• A) Cheese – Microorganisms used.
• B) Antibiotics – Produced using microbes.
• C) Internet – Correct, not biotechnology.
• D) Fermentation – Biotech application.

Q45. Which gas is essential for burning?

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

✅ Correct Answer: B) Oxygen

Explanation:

• A) CO₂ – Does not support burning.
• B) Oxygen – Correct, required for combustion.
• C) Nitrogen – Inert gas, does not support fire.
• D) Hydrogen – Flammable but not supporter of burning.

Q46. Which Indian scientist worked on plant physiology and invented crescograph?

A) C.V. Raman
B) J.C. Bose
C) Homi Bhabha
D) Satyendra Nath Bose

✅ Correct Answer: B) J.C. Bose

Explanation:

• A) Raman – Physics.
• B) J.C. Bose – Correct, studied plants and invented crescograph.
• C) Bhabha – Nuclear research.
• D) S.N. Bose – Quantum physics.

Q47. Which of these is an example of chemical change in daily life?

A) Tearing paper
B) Freezing water
C) Burning wood
D) Melting wax

✅ Correct Answer: C) Burning wood

Explanation:

• A) Tearing – Physical change.
• B) Freezing – Physical change.
• C) Burning wood – Correct, irreversible chemical change.
• D) Melting wax – Physical change.

Q48. Which of these devices converts electrical energy into mechanical energy?

A) Electric motor
B) Electric bulb
C) Heater
D) Battery

✅ Correct Answer: A) Electric motor

Explanation:

• A) Motor – Correct, converts electricity to motion.
• B) Bulb – Converts electricity to light.
• C) Heater – Converts electricity to heat.
• D) Battery – Converts chemical to electrical energy.

Q49. Which of these discoveries helped in curing many diseases?

A) Telescope
B) Microscope
C) Antibiotics
D) Thermometer

✅ Correct Answer: C) Antibiotics

Explanation:

• A) Telescope – For space, not curing.
• B) Microscope – Helped study microbes, indirectly helpful.
• C) Antibiotics – Correct, directly cures bacterial diseases.
• D) Thermometer – Measures temperature, not cure.

Q50. Which scientific method step comes after hypothesis?

A) Observation
B) Conclusion
C) Experimentation
D) Guesswork

✅ Correct Answer: C) Experimentation

Explanation:

• A) Observation – First step.
• B) Conclusion – Comes at the end.
• C) Experimentation – Correct, tests hypothesis.
• D) Guesswork – Not part of scientific method.

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