1. Who invented the telescope?
a) Newton
b) Galileo
c) Herschel
d) Kepler
Answer: b
Explanation: Galileo improved the refracting telescope in 1609 to observe celestial bodies.
2. The reflecting telescope was invented by:
a) Newton
b) Galileo
c) Herschel
d) Huygens
Answer: a
Explanation: Isaac Newton invented the first reflecting telescope in 1668 using a mirror.
3. Who discovered the law of universal gravitation?
a) Newton
b) Galileo
c) Kepler
d) Einstein
Answer: a
Explanation: Newton formulated gravitational force law in 1687.
4. Pendulum clock was invented by:
a) Huygens
b) Galileo
c) Newton
d) Edison
Answer: a
Explanation: Christiaan Huygens invented the pendulum clock in 1656 for accurate timekeeping.
5. The first barometer was invented by:
a) Torricelli
b) Pascal
c) Boyle
d) Newton
Answer: a
Explanation: Torricelli (1643) created mercury barometer to measure atmospheric pressure.
6. Who discovered buoyancy principle?
a) Archimedes
b) Newton
c) Galileo
d) Pascal
Answer: a
Explanation: Archimedes formulated buoyancy law in ancient Greece.
7. The first electric battery (Voltaic pile) was invented by:
a) Volta
b) Faraday
c) Ohm
d) Ampere
Answer: a
Explanation: Alessandro Volta invented the first battery in 1800.
8. Leyden jar is used to store:
a) Current
b) Voltage
c) Charge
d) Resistance
Answer: c
Explanation: Leyden jar is an early capacitor to store electric charge.
9. Who discovered the electron?
a) Thomson
b) Rutherford
c) Bohr
d) Einstein
Answer: a
Explanation: J.J. Thomson discovered the electron in 1897 via cathode ray experiments.
10. Who discovered radioactivity?
a) Becquerel
b) Curie
c) Rutherford
d) Chadwick
Answer: a
Explanation: Henri Becquerel discovered natural radioactivity in 1896.
11. X-rays were discovered by:
a) Röntgen
b) Becquerel
c) Thomson
d) Curie
Answer: a
Explanation: Wilhelm Röntgen discovered X-rays in 1895.
12. Cathode rays led to discovery of:
a) Proton
b) Electron
c) Neutron
d) Photon
Answer: b
Explanation: Cathode rays are streams of electrons, discovered by J.J. Thomson.
13. Who invented the mechanical calculator?
a) Pascal
b) Leibniz
c) Babbage
d) Turing
Answer: a
Explanation: Blaise Pascal invented Pascaline in 1642 for addition/subtraction.
14. The first programmable computer concept was given by:
a) Babbage
b) Turing
c) Leibniz
d) Pascal
Answer: a
Explanation: Charles Babbage designed the Analytical Engine in 1837.
15. The first successful radio communication was by:
a) Marconi
b) Tesla
c) Hertz
d) Faraday
Answer: a
Explanation: Marconi transmitted wireless signals in 1895–1901.
16. Who discovered electromagnetic induction?
a) Faraday
b) Maxwell
c) Ampere
d) Ohm
Answer: a
Explanation: Faraday discovered induction in 1831 using coil and magnet.
17. Who formulated the laws of electrolysis?
a) Faraday
b) Coulomb
c) Ohm
d) Ampere
Answer: a
Explanation: Faraday’s laws of electrolysis relate charge and amount of substance deposited.
18. Who invented the dynamo?
a) Faraday
b) Volta
c) Tesla
d) Edison
Answer: a
Explanation: Faraday built first electromagnetic generator in 1831.
19. Who discovered the neutron?
a) Rutherford
b) Chadwick
c) Bohr
d) Curie
Answer: b
Explanation: James Chadwick discovered neutron in 1932.
20. Who invented the first electric motor?
a) Faraday
b) Volta
c) Edison
d) Tesla
Answer: a
Explanation: Faraday demonstrated first motor using current-carrying wire in magnetic field.
21. Who discovered the photoelectric effect?
a) Hertz
b) Einstein
c) Thomson
d) Faraday
Answer: a
Explanation: Heinrich Hertz observed electron emission from metals under light in 1887; Einstein explained it in 1905.
22. Who explained the quantum nature of light?
a) Planck
b) Einstein
c) Bohr
d) Rutherford
Answer: b
Explanation: Einstein proposed light quanta (photons) in 1905.
23. Who invented the first thermometer?
a) Galileo
b) Fahrenheit
c) Celsius
d) Kelvin
Answer: a
Explanation: Galileo invented thermoscope (~1592); later Fahrenheit and Celsius developed scales.
24. Fahrenheit scale was proposed by:
a) Fahrenheit
b) Celsius
c) Kelvin
d) Réaumur
Answer: a
Explanation: Gabriel Fahrenheit proposed scale in 1724.
25. Celsius temperature scale was introduced by:
a) Fahrenheit
b) Celsius
c) Kelvin
d) Réaumur
Answer: b
Explanation: Anders Celsius proposed centigrade scale in 1742.
26. Who invented the first practical electric generator?
a) Faraday
b) Gramme
c) Edison
d) Tesla
Answer: b
Explanation: Zénobe Gramme invented the first commercial DC generator in 1869.
27. Who invented the alternating current (AC) generator?
a) Faraday
b) Tesla
c) Edison
d) Marconi
Answer: b
Explanation: Nikola Tesla developed AC generators and promoted AC transmission.
28. Who invented the transformer?
a) Faraday
b) Tesla
c) Gaulard and Gibbs
d) Edison
Answer: c
Explanation: Gaulard and Gibbs developed early transformer design in 1880s.
29. Ohm’s law was formulated by:
a) Ohm
b) Faraday
c) Ampere
d) Maxwell
Answer: a
Explanation: Ohm’s law was formulated by the German physicist Georg Simon Ohm in 1827. His work established the relationship between voltage ((V)), current ((I)), and resistance ((R)) in an electrical circuit, which can be expressed mathematically as (V=I\times R).
30. Ampere’s law relates:
a) Current and voltage
b) Magnetic field around current-carrying conductor
c) Resistance and current
d) Electric field and charge
Answer: b
Explanation: Ampere showed magnetic field proportional to current and geometry.
31. Who invented the telegraph?
a) Morse
b) Bell
c) Edison
d) Marconi
Answer: a
Explanation: Samuel Morse developed electrical telegraph and Morse code in 1837–1844.
32. Who invented the telephone?
a) Bell
b) Edison
c) Marconi
d) Faraday
Answer: a
Explanation: Alexander Graham Bell patented telephone in 1876.
33. Who invented the incandescent light bulb?
a) Edison
b) Tesla
c) Faraday
d) Volta
Answer: a
Explanation: Edison developed practical long-lasting bulb in 1879.
34. Alternating current was promoted over DC by:
a) Edison
b) Tesla
c) Faraday
d) Ohm
Answer: b
Explanation: Tesla demonstrated AC’s advantages in transmission efficiency.
35. Fleming’s diode was invented in:
a) 1870
b) 1904
c) 1895
d) 1910
Answer: b
Explanation: John Ambrose Fleming invented vacuum tube diode in 1904.
36. Who invented the triode vacuum tube?
a) Fleming
b) De Forest
c) Tesla
d) Edison
Answer: b
Explanation: Lee De Forest invented triode (“Audion”) in 1906 to amplify signals.
37. Who discovered electromagnetic waves?
a) Maxwell
b) Hertz
c) Faraday
d) Tesla
Answer: b
Explanation: Heinrich Hertz (1887) generated and detected radio waves, confirming Maxwell’s theory.
38. Maxwell’s contribution to electromagnetism:
a) Unified electricity and magnetism
b) Discovered electron
c) Invented battery
d) Developed telegraph
Answer: a
Explanation: Maxwell formulated equations describing electric and magnetic fields (1860s).
39. Who invented the electric arc lamp?
a) Davy
b) Edison
c) Tesla
d) Faraday
Answer: a
Explanation: Humphry Davy created first electric arc lamp in 1806.
40. Who invented the induction motor?
a) Tesla
b) Edison
c) Faraday
d) Marconi
Answer: a
Explanation: Tesla developed AC induction motor in 1888.
41. The first practical electric battery was by:
a) Volta
b) Faraday
c) Edison
d) Ohm
Answer: a
Explanation: Alessandro Volta (1800) developed the voltaic pile, first reliable current source.
42. Faraday’s law of induction states:
a) EMF is proportional to rate of change of magnetic flux
b) Current is proportional to voltage
c) Resistance is proportional to temperature
d) Magnetic field is proportional to current
Answer: a
Explanation: Faraday’s Law of Electromagnetic Induction states that the induced electromotive force (EMF) in a closed circuit is directly proportional to the rate of change of magnetic flux through the circuit.
43. Who discovered the Hall effect?
a) Hall
b) Tesla
c) Faraday
d) Maxwell
Answer: a
Explanation: Edwin Hall (1879) observed voltage perpendicular to current and magnetic field in conductor.
44. Tesla coil is used to:
a) Measure current
b) Produce high-voltage AC
c) Generate DC
d) Amplify signals
Answer: b
Explanation: Produces high-frequency, high-voltage AC.
45. Who invented the first electric fan?
a) Edison
b) Tesla
c) Faraday
d) Franklin
Answer: a
Explanation: Edison developed first commercial electric fan in late 19th century.
46. Who discovered the principle of electromagnetic relay?
a) Joseph Henry
b) Faraday
c) Edison
d) Tesla
Answer: a
Explanation: Joseph Henry (1835) developed relay principle, later used in telegraphy.
47. Who invented the induction coil?
a) Ruhmkorff
b) Faraday
c) Tesla
d) Edison
Answer: a
Explanation: Heinrich Ruhmkorff (1851) created induction coil to produce high-voltage pulses.
48. Who invented electric welding?
a) Elihu Thomson
b) Edison
c) Faraday
d) Tesla
Answer: a
Explanation: Elihu Thomson developed arc welding process using electricity in late 19th century.
49. Who developed the first electric railway?
a) Siemens
b) Edison
c) Tesla
d) Faraday
Answer: a
Explanation: Werner von Siemens (1879) built first electric tramway in Germany.
50. Who invented the fluorescent lamp?
a) Edison
b) Tesla
c) Peter Cooper Hewitt
d) Faraday
Answer: c
Explanation: Peter Cooper Hewitt (1901) developed mercury vapor fluorescent lamp.
51. Who proposed the quantum theory of light?
a) Planck
b) Einstein
c) Bohr
d) Rutherford
Answer: a
Explanation: Max Planck (1900) introduced quantized energy to explain blackbody radiation.
52. Who explained the photoelectric effect?
a) Planck
b) Einstein
c) Thomson
d) Bohr
Answer: b
Explanation: The photoelectric effect was explained by Albert Einstein in 1905. He proposed that light consists of discrete packets of energy called photons.
53. Who proposed the Bohr model of the atom?
a) Rutherford
b) Bohr
c) Thomson
d) Chadwick
Answer: b
Explanation: Bohr (1913) introduced quantized electron orbits to explain hydrogen spectra.
54. Who discovered the neutron?
a) Rutherford
b) Chadwick
c) Thomson
d) Curie
Answer: b
Explanation: James Chadwick (1932) discovered neutral particles in the nucleus.
55. Who discovered the proton?
a) Rutherford
b) Chadwick
c) Thomson
d) Einstein
Answer: a
Explanation: Rutherford (1917) identified the nucleus and proton via scattering experiments.
56. Who discovered nuclear fission?
a) Hahn and Strassmann
b) Einstein
c) Curie
d) Bohr
Answer: a
Explanation: Otto Hahn and Fritz Strassmann (1938) discovered fission of uranium nuclei.
57. Who developed the first nuclear reactor?
a) Fermi
b) Rutherford
c) Einstein
d) Bohr
Answer: a
Explanation: Enrico Fermi (1942) created first controlled chain reaction in Chicago Pile-1.
58. Who discovered radioactivity?
a) Becquerel
b) Curie
c) Rutherford
d) Chadwick
Answer: a
Explanation: Henri Becquerel (1896) discovered uranium salts emit radiation spontaneously.
59. Who discovered alpha and beta rays?
a) Rutherford
b) Becquerel
c) Curie
d) Thomson
Answer: a
Explanation: Rutherford (1899–1903) identified α (helium nuclei) and β (electrons) radiation.
60. Who invented the cyclotron?
a) Lawrence
b) Rutherford
c) Bohr
d) Tesla
Answer: a
Explanation: Ernest Lawrence (1930) developed cyclotron to accelerate charged particles.
61. Who discovered the positron?
a) Anderson
b) Chadwick
c) Rutherford
d) Bohr
Answer: a
Explanation: Carl Anderson (1932) discovered positron in cosmic rays.
62. Who proposed mass-energy equivalence 
?
a) Einstein
b) Planck
c) Rutherford
d) Bohr
Answer: a
Explanation: Einstein (1905) showed energy and mass are equivalent in special relativity.
63. Who discovered artificial radioactivity?
a) Irène Joliot-Curie
b) Marie Curie
c) Rutherford
d) Fermi
Answer: a
Explanation: Irène Joliot-Curie (1934) induced radioactivity in stable elements using alpha particles.
64. Who discovered gamma rays?
a) Rutherford
b) Becquerel
c) Thomson
d) Curie
Answer: a
Explanation: Rutherford (1903) identified gamma rays as high-energy electromagnetic radiation from nuclei.
65. Who developed the liquid drop model of nucleus?
a) Bohr
b) Gamow
c) Rutherford
d) Fermi
Answer: b
Explanation: George Gamow proposed the liquid drop analogy to explain nuclear fission.
66. Who discovered the electron diffraction phenomenon?
a) Davisson and Germer
b) Thomson
c) Rutherford
d) Bohr
Answer: a
Explanation: Davisson and Germer (1927) confirmed wave nature of electrons.
67. Who developed quantum mechanics?
a) Heisenberg, Schrödinger, Dirac
b) Bohr
c) Rutherford
d) Einstein
Answer: a
Explanation: Modern quantum mechanics was formulated in 1925–1928 by Heisenberg, Schrödinger, and Dirac.
68. Who discovered the muon?
a) Anderson
b) Lawrence
c) Rutherford
d) Bohr
Answer: a
Explanation: Carl Anderson (1936) observed muon in cosmic rays.
69. Who invented the bubble chamber?
a) Glaser
b) Rutherford
c) Bohr
d) Lawrence
Answer: a
Explanation: Donald Glaser (1952) developed bubble chamber to track charged particles.
70. Who discovered the neutrino?
a) Pauli
b) Fermi
c) Chadwick
d) Bohr
Answer: a
Explanation: Wolfgang Pauli (1930) proposed neutrino to conserve energy in beta decay.
71. Who first split the atom?
a) Rutherford
b) Fermi
c) Bohr
d) Chadwick
Answer: a
Explanation: Rutherford (1917) bombarded nitrogen with alpha particles, ejecting protons.
72. Who developed the first nuclear bomb?
a) Oppenheimer
b) Fermi
c) Bohr
d) Rutherford
Answer: a
Explanation: J. Robert Oppenheimer led Manhattan Project (1945) developing atomic bomb.
73. Who discovered the concept of half-life?
a) Rutherford
b) Curie
c) Becquerel
d) Fermi
Answer: a
Explanation: Rutherford introduced half-life to describe radioactive decay rates.
74. Who invented the Geiger-Müller counter?
a) Geiger and Müller
b) Rutherford
c) Curie
d) Becquerel
Answer: a
Explanation: Hans Geiger and Walther Müller (1928) developed GM counter for radiation detection.
75. Who invented the cloud chamber?
a) Wilson
b) Rutherford
c) Fermi
d) Chadwick
Answer: a
Explanation: Charles Wilson (1911) invented cloud chamber to visualize particle tracks.
76. Who invented the first practical photophone?
a) Bell
b) Edison
c) Tesla
d) Marconi
Answer: a
Explanation: Alexander Graham Bell (1880) invented photophone to transmit voice using light.
77. Who invented the laser?
a) Maiman
b) Einstein
c) Bohr
d) Fermi
Answer: a
Explanation: Theodore Maiman (1960) built first working ruby laser.
78. Who invented fiber optics for communication?
a) Kao
b) Bell
c) Tesla
d) Edison
Answer: a
Explanation: Charles K. Kao (1966) proposed low-loss optical fibers for telecommunication.
79. Who discovered the principle of holography?
a) Gabor
b) Einstein
c) Bohr
d) Tesla
Answer: a
Explanation: Dennis Gabor (1947) invented holography to record and reconstruct 3D images.
80. Who invented the first LCD display?
a) Heilmeier
b) Tesla
c) Bell
d) Edison
Answer: a
Explanation: George H. Heilmeier (1968) developed first practical liquid crystal display.
81. Who invented the charge-coupled device (CCD)?
a) Boyle and Smith
b) Tesla
c) Bell
d) Edison
Answer: a
Explanation: Willard Boyle and George Smith (1969) invented CCD for digital imaging.
82. Who invented the first transistor?
a) Bardeen, Brattain, Shockley
b) Einstein
c) Bohr
d) Fermi
Answer: a
Explanation: Bell Labs scientists (1947) invented transistor to amplify electrical signals.
83. Who invented the first integrated circuit (IC)?
a) Kilby
b) Shockley
c) Bardeen
d) Bohr
Answer: a
Explanation: Jack Kilby (1958) developed first monolithic IC.
84. Who discovered X-rays?
a) Röntgen
b) Tesla
c) Edison
d) Curie
Answer: a
Explanation: Wilhelm Röntgen (1895) discovered X-rays while experimenting with cathode rays.
85. Who invented the first radio?
a) Marconi
b) Tesla
c) Hertz
d) Edison
Answer: a
Explanation: Guglielmo Marconi (1895–1901) transmitted wireless signals over long distance.
86. Who demonstrated electromagnetic waves experimentally?
a) Hertz
b) Marconi
c) Tesla
d) Edison
Answer: a
Explanation: Heinrich Hertz (1887) confirmed Maxwell’s theory by generating and detecting radio waves.
87. Who invented the first practical microwave oven?
a) Percy Spencer
b) Tesla
c) Marconi
d) Edison
Answer: a
Explanation: Percy Spencer (1945) used magnetron-generated microwaves to cook food.
88. Who developed the first LED?
a) Holonyak
b) Einstein
c) Bohr
d) Tesla
Answer: a
Explanation: Nick Holonyak Jr. (1962) developed first visible red LED.
89. Who invented the first photovoltaic cell?
a) Chapin, Fuller, Pearson
b) Tesla
c) Edison
d) Marconi
Answer: a
Explanation: Bell Labs team (1954) developed first practical solar cell using silicon.
90. Who invented the optical fiber amplifier?
a) Charles Kao
b) Townes
c) Marconi
d) Bell
Answer: b
Explanation: Charles Townes and colleagues developed optical amplifiers to boost fiber optic signals.
91. Who developed the first electron microscope?
a) Ruska
b) Röntgen
c) Hertz
d) Tesla
Answer: a
Explanation: Ernst Ruska (1931) developed first electron microscope for high-resolution imaging.
92. Who invented the first gamma-ray telescope?
a) Kraushaar
b) Röntgen
c) Hertz
d) Marconi
Answer: a
Explanation: Robert Kraushaar (1960s) developed gamma-ray telescope to detect cosmic gamma radiation.
93. Who invented the first PET scanner?
a) David E. Kuhl
b) Röntgen
c) Tesla
d) Marconi
Answer: a
Explanation: Kuhl and Edwards (1950s–1960s) developed positron emission tomography for medical imaging.
94. Who developed sonar for detecting submarines?
a) Lewis Nixon
b) Marconi
c) Tesla
d) Edison
Answer: a
Explanation: Lewis Nixon (WWI era) developed active sonar using sound waves underwater.
95. Who invented the cathode ray tube (CRT)?
a) Braun
b) Röntgen
c) Hertz
d) Tesla
Answer: a
Explanation: Ferdinand Braun (1897) developed CRT for oscilloscopes and early TVs.
96. Who invented the first X-ray spectrometer?
a) von Laue
b) Röntgen
c) Hertz
d) Tesla
Answer: a
Explanation: Max von Laue (1912) used X-ray diffraction to study crystal structure.
97. Who developed the first atomic clock?
a) Essen
b) Rabi
c) Tesla
d) Bohr
Answer: a
Explanation: Louis Essen (1955) developed cesium atomic clock for precise time measurement.
98. Who invented the cathodoluminescent screen?
a) Crookes
b) Röntgen
c) Hertz
d) Tesla
Answer: a
Explanation: William Crookes (1897) developed screens that emit light when struck by electrons.
99. Who developed radar technology?
a) Watson-Watt
b) Marconi
c) Tesla
d) Edison
Answer: a
Explanation: Robert Watson-Watt (1935) developed radar for detecting aircraft.
100. Who invented the first practical digital camera?
a) Steven Sasson
b) Boyle
c) Bell
d) Tesla
Answer: a
Explanation: Steven Sasson (1975) at Kodak developed first working digital camera prototype.