All Free Physics MCQs with Answers
Every Physics question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,934 questions · page 687 of 697
- A. Wave-particle duality
- B. Only wave nature
- C. Only particle nature
- D. Neither wave nor particle nature
Explanation: According to debroglie , all mater particles in motion have dual nature and thus he derived an equation which is E=hc/λ
Correct answer: Wave-particle duality- A. 7.3 × 10 -34 m
- B. 1.1 × 10 -34 m
- C. 1.8 × 10 -35 m
- D. 9.9 × 10 -34 m
Explanation: λ= h/mv = 6.626 x 10-34 / 0.02 x 300 = 1.1 × 10 -34 m
Correct answer: 1.1 × 10 -34 m- A. The photoelectric effect
- B. The Compton effect
- C. The spectral radiation form cavity radiation
- D. The reflection of electrons by crystal
Explanation: By Huygens principle, reflection of electrons shows the wave nature of light. So, D is the answer.
Correct answer: The reflection of electrons by crystal- A. Line spectra of action
- B. The production of x-rays
- C. The photoelectric erect
- D. Electrons diffraction by crystalline material
Explanation: The wave properties of electrons can be demonstrated through diffraction, superposition and interference.
Correct answer: Electrons diffraction by crystalline material- A. Occurs at the same time
- B. Occur at the same co-ordinates
- C. Are separated by the distance a light signal can travel during the time interval
- D. Satisfy none of the above
Explanation: The proper time interval between two events is the amount of elapsed time reckoned on the clock of an observer in an inertial frame of…
Correct answer: Occur at the same co-ordinates- A. 0.2 nm
- B. 2 nm
- C. 0.02 nm
- D. 2 Å
Explanation: To find the minimum wavelength of X-rays produced in an X-ray tube, we use the formula: 𝝺min = hc/qeV, where:h is Planck's constant…
Correct answer: 0.02 nm- A. Distance
- B. Speed
- C. Time
- D. Energy
Explanation: Einstein's theory of relativity introduced the revolutionary concept of spacetime, where the three dimensions of space are intertwined…
Correct answer: Time- A. A
- B. B
- C. C
- D. D
Explanation: The problem defines a "Proton volt" as the energy gained by a proton (charge qp =+e) when it moves through an electric potential…
Correct answer: A- A. Angular Momentum
- B. Work
- C. Force
- D. Torque
Explanation: The unit of planck's constant is equivalent to that of angular momentum.
Correct answer: Angular Momentum- A. He only
- B. Ne only
- C. Both He and Ne
- D. None of the above
Explanation: In a He-Ne laser, the active material is a mixture of helium (He) and neon (Ne) gases.
Correct answer: Both He and Ne13731. Raleigh Jean predicted behavior of black body radiations, this predictions came to conclusion that:
- A. Explained with quantum theory
- B. Explained well by mathematical treatment
- C. Failed to explain ultraviolet region
- D. Used Einstein's theory of relativity
Explanation: Raleigh-Jean did make predictions about black body radiation, but those predictions couldn't explain the behavior in the ultraviolet (UV)…
Correct answer: Failed to explain ultraviolet region- A. A proton
- B. A neutron
- C. An alpha particle
- D. a beta particle
Explanation: Beta decay is a radioactive decay in which a beta ray is emitted from an atomic nucleus.
Correct answer: a beta particle- A. Increase
- B. Remain the same
- C. Decrease
- D. Increase or decrease depending upon the temperature of the substance
Explanation: Radioactivity is always random and spontaneous. Random means one cannot know precisely when the next decay will happen, though one can…
Correct answer: Remain the same- A. 83Bi212
- B. 81Bi210
- C. 85Bi210
- D. None of these
Explanation: When a β-particle, which is an electron, is emitted from the nucleus during beta decay, a neutron is transformed into a proton.
Correct answer: 83Bi212- A. one Becquerel
- B. One curie
- C. One-half life
- D. None of above
Explanation: One becquerel is the quantity of a radioactive element in which there is one atomic disintegration per second.
Correct answer: One curie- A. 92U235
- B. 92U236
- C. 92U238
- D. 92U239
Explanation: 92U235 is the only naturally occurring isotope of uranium that is fissile (able to fission with slow neutrons).
Correct answer: 92U235- A. No charge
- B. Non-material nature
- C. Small size
- D. Lighter particles
Explanation: Gamma rays have higher penetrating power than alpha and beta particles due to their lack of charge.
Correct answer: No charge- A. Cyclotron
- B. Betatron
- C. Accelerator
- D. Nuclear reactor
Explanation: The device in which the controlled fission chain reaction is maintained is called a nuclear reactor.
Correct answer: Nuclear reactor- A. 90Rn^220
- B. 86Rn^222
- C. 89Rn^226
- D. 90Rn^222
Explanation: When an alpha particle is emitted, the mass number of the daughter nucleus will decrease by 4, and the charge number will decrease by 2.
Correct answer: 86Rn^222- A. fission
- B. beta decay
- C. alpha radiation
- D. gamma radiation
Explanation: URANIUM-238 : Mass number : 238 Atomic number : 92 THORIUM-234 : Mass number : 234 Atomic number: 90 From above, it is clear that mass…
Correct answer: alpha radiation