Famous Scientists & Discoveries — Homi Bhabha Class 9 General Knowledge MCQs with Solutions
Free Homi Bhabha Class 9 General Knowledge Famous Scientists & Discoveries MCQs with step-by-step solutions (25 questions). Part of Scientists & Nobel Laureates. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Famous Scientists & Discoveries · medium · theory
The laws of motion and the law of universal gravitation were given by:
A. Albert Einstein
B. Michael Faraday
C. Isaac Newton ✓ Correct
D. Galileo Galilei
Solution: Sir Isaac Newton formulated the three laws of motion and the law of gravitation.
Q2 — Famous Scientists & Discoveries · medium · theory
The famous equation E = mc² and the theory of relativity were given by:
A. Niels Bohr
B. C. V. Raman
C. Isaac Newton
D. Albert Einstein ✓ Correct
Solution: Albert Einstein proposed the theory of relativity and the mass–energy relation E = mc².
Q3 — Famous Scientists & Discoveries · hard · theory
The theory of evolution by natural selection was proposed by:
A. Charles Darwin ✓ Correct
B. Louis Pasteur
C. Gregor Mendel
D. Robert Hooke
Solution: Charles Darwin explained evolution through natural selection in "On the Origin of Species".
Q4 — Famous Scientists & Discoveries · medium · theory
The scientist who discovered the electron was:
A. J. J. Thomson ✓ Correct
B. James Chadwick
C. Ernest Rutherford
D. John Dalton
Solution: J. J. Thomson discovered the electron in 1897.
Q5 — Famous Scientists & Discoveries · hard · theory
The nucleus of the atom was discovered by:
A. Niels Bohr
B. John Dalton
C. J. J. Thomson
D. Ernest Rutherford ✓ Correct
Solution: Rutherford's gold-foil experiment revealed the tiny, dense, positive nucleus.
Q6 — Famous Scientists & Discoveries · medium · theory
The antibiotic penicillin was discovered by:
A. Edward Jenner
B. Louis Pasteur
C. Alexander Fleming ✓ Correct
D. Robert Koch
Solution: Alexander Fleming discovered penicillin from the mould Penicillium in 1928.
Q7 — Famous Scientists & Discoveries · hard · theory
The first successful vaccine (against smallpox) was developed by:
A. Alexander Fleming
B. Edward Jenner ✓ Correct
C. Jonas Salk
D. Louis Pasteur
Solution: Edward Jenner developed the smallpox vaccine in 1796.
Q8 — Famous Scientists & Discoveries · medium · theory
The telephone was invented by:
A. Thomas Edison
B. Nikola Tesla
C. Alexander Graham Bell ✓ Correct
D. Guglielmo Marconi
Solution: Alexander Graham Bell is credited with inventing the telephone in 1876.
Q9 — Famous Scientists & Discoveries · medium · theory
The electric light bulb was developed by:
A. Michael Faraday
B. Alexander Bell
C. James Watt
D. Thomas Edison ✓ Correct
Solution: Thomas Edison developed a practical incandescent light bulb.
Q10 — Famous Scientists & Discoveries · hard · theory
The phenomenon of electromagnetic induction (basis of generators) was discovered by:
A. Isaac Newton
B. Michael Faraday ✓ Correct
C. Alessandro Volta
D. Georg Ohm
Solution: Michael Faraday discovered electromagnetic induction in 1831.
Q11 — Famous Scientists & Discoveries · hard · theory
The principle of buoyancy ("a body immersed in a fluid is buoyed up...") was given by:
A. Pascal
B. Newton
C. Aristotle
D. Archimedes ✓ Correct
Solution: Archimedes' principle describes the upthrust on a body immersed in a fluid.
Q12 — Famous Scientists & Discoveries · medium · theory
The father of genetics, who experimented on pea plants, was:
A. Watson
B. Hooke
C. Gregor Mendel ✓ Correct
D. Charles Darwin
Solution: Gregor Mendel established the basic laws of heredity.
Q13 — Famous Scientists & Discoveries · hard · theory
The scientist who greatly advanced the study of radioactivity and discovered radium was:
A. Michael Faraday
B. Charles Darwin
C. Marie Curie ✓ Correct
D. Isaac Newton
Solution: Marie Curie pioneered research on radioactivity and discovered radium and polonium.
Q14 — Famous Scientists & Discoveries · medium · theory
The first powered aeroplane was built and flown by the:
A. Curie sisters
B. Wright brothers ✓ Correct
C. Bernoulli brothers
D. Newton brothers
Solution: Orville and Wilbur Wright made the first powered flight in 1903.
Q15 — Famous Scientists & Discoveries · hard · theory
Galileo Galilei is famous for improving the telescope and for supporting the idea that:
A. the Earth is flat
B. the Sun revolves around the Earth
C. the Moon produces its own light
D. the Earth revolves around the Sun ✓ Correct
Solution: Galileo supported the heliocentric (Sun-centred) model using telescopic observations.
Q16 — Famous Scientists & Discoveries · easy · theory
The first electric battery, the voltaic pile, was invented by:
A. Alessandro Volta ✓ Correct
B. Andre-Marie Ampere
C. Charles Coulomb
D. Georg Ohm
Solution: Alessandro Volta built the first electric battery, the voltaic pile, in 1800.
Q17 — Famous Scientists & Discoveries · easy · theory
The neutron, the neutral particle found inside the atomic nucleus, was discovered by:
A. J. J. Thomson
B. Ernest Rutherford
C. Niels Bohr
D. James Chadwick ✓ Correct
Solution: James Chadwick discovered the neutron in 1932.
Q18 — Famous Scientists & Discoveries · easy · theory
X-rays, used today to photograph broken bones, were discovered by:
A. Wilhelm Roentgen ✓ Correct
B. Max Planck
C. Henri Becquerel
D. Marie Curie
Solution: Wilhelm Roentgen discovered X-rays in 1895.
Q19 — Famous Scientists & Discoveries · easy · theory
The modern atomic theory, stating that all matter is made of tiny atoms, was proposed by:
A. J. J. Thomson
B. Niels Bohr
C. John Dalton ✓ Correct
D. Democritus
Solution: John Dalton gave the modern atomic theory; Democritus only had an early philosophical idea of atoms.
Q20 — Famous Scientists & Discoveries · medium · theory
Pasteurization, the gentle heating of milk to kill harmful microbes, is named after the scientist who also disproved spontaneous generation:
A. Alexander Fleming
B. Louis Pasteur ✓ Correct
C. Robert Koch
D. Edward Jenner
Solution: Louis Pasteur developed pasteurization and disproved the idea of spontaneous generation of life.
Q21 — Famous Scientists & Discoveries · medium · theory
The Indian scientist J. C. Bose is best remembered for using his crescograph to show that:
A. plants respond to stimuli like light and touch ✓ Correct
B. plants breathe only during the night
C. plants make food without any sunlight
D. plants have no life at all
Solution: J. C. Bose used the crescograph to demonstrate that plants respond to stimuli such as light and touch.
Q22 — Famous Scientists & Discoveries · medium · theory
Assertion: A glass prism splits white light into a band of seven colours. Reason: White light is a mixture of several colours, first shown by Isaac Newton. Choose the correct option:
A. The assertion is false but the reason is true
B. Both are true, but the reason does not explain the assertion
C. The assertion is true but the reason is false
D. Both assertion and reason are true, and the reason correctly explains the assertion ✓ Correct
Solution: Newton showed white light is a mixture of colours that a prism separates, so the reason correctly explains the assertion.
Q23 — Famous Scientists & Discoveries · hard · theory
The scientist who found that a current-carrying wire deflects a nearby magnetic compass needle, thereby linking electricity and magnetism, was:
A. Michael Faraday
B. Georg Ohm
C. Hans Christian Oersted ✓ Correct
D. Andre-Marie Ampere
Solution: Hans Christian Oersted showed in 1820 that an electric current deflects a compass needle, connecting electricity and magnetism.
Q24 — Famous Scientists & Discoveries · hard · theory
The law stating that the current through a conductor is directly proportional to the voltage across it (V = I × R) was given by:
A. Alessandro Volta
B. Andre-Marie Ampere
C. Georg Ohm ✓ Correct
D. James Joule
Solution: Ohm gave the law V = I × R relating voltage, current and resistance.
Q25 — Famous Scientists & Discoveries · hard · theory
Two students argue about who first proposed that the Sun, not the Earth, is at the centre of the solar system. The astronomer who first proposed this heliocentric model, long before Galileo defended it, was:
A. Johannes Kepler
B. Galileo Galilei
C. Nicolaus Copernicus ✓ Correct
D. Isaac Newton
Solution: Nicolaus Copernicus first proposed the Sun-centred model; Galileo later defended it using his telescope.