Free Dawn of Modern Physics MCQs with Answers

• A. Sound waves
• B. Light waves
• C. Heat waves
• D. X-rays

Explanation: Sound waves require a material medium for their propagation. Sound is a mechanical wave that involves the transfer of energy through…

• A. De-Broglie
• B. Faraday
• C. Michelson and Morley
• D. Einstein

Explanation: The existence of the "ether wind" was experimentally rejected by the Michelson-Morley experiment conducted by Albert A.

• A. Einstein
• B. Morley
• C. Michelson
• D. De-Broglie

Explanation: In 1905, the theory of relativity was proposed by Albert Einstein. Specifically, Einstein formulated the special theory of relativity in…

• A. All laws of physics are the same in every inertial frame of reference
• B. Speed of light in free space is a universal constant
• C. Speed of light is independent of the speed of observer
• D. All of the above

Explanation: The statement "All laws of physics are the same in every inertial frame of reference" is a fundamental principle known as the Principle of…

• A. Mass
• B. Length
• C. Time
• D. All of these

Explanation: The physical quantity that changes with relativistic speed according to Einstein's theory of special relativity is mass.

• A. 2.6 x 10^8 m/s
• B. 1.6 x 10^8 m/s
• C. 2.6 x 10^-8 m/s
• D. None of these

Explanation: Explanation is given below in the attached image.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Explanation is given below in the attached image.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Explanation is given below in the attached image.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Energy-mass relationship is given by: E = mc^2 This equation states that mass and energy are interchangeable and are related by a constant…

• A. 9 x 10^8 Joules
• B. 9 x 10^16 Joules
• C. 9 x 10^10 Joules
• D. 6 x 10^16 Joules

Explanation: Explanation is given below in the attached image.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Explanation is given below in the attached image.

• A. The mass of the objects are very large
• B. The size of the objects are very small
• C. The speed of the objects are very small as compared to speed of light
• D. None of the above

Explanation: The relativistic effects become noticeable only at speeds approaching the speed of light, which is much higher than typical speeds in…

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: According to Einstein's mass-energy equivalence principle E = mc^2, the energy of photon is equivalent to mass.

• A. Hertz
• B. Max Planck
• C. J.J. Thomson
• D. Rayleigh-Jean

Explanation: The discrete nature of radiation was introduced by Max Planck in 1900 when he proposed the concept of quantized energy levels to explain…

• A. Milikan
• B. J. J. Thomson
• C. Chadwick
• D. Bohr

Explanation: The electron was discovered by J.J. Thomson in 1897 through his cathode ray tube experiments.

• A. Shifts towards longer wavelength
• B. Shifts towards shorter wavelength
• C. Remains the same
• D. None of these

Explanation: As the temperature of a black body is raised, the wavelength corresponding to the maximum intensity of its emitted radiation decreases.

• A. J. J. Thomson
• B. Rutherford
• C. Einstein
• D. Hertz

Explanation: Planck's work led Einstein in determining that light exists in discrete quanta of energy, or photons.

• A. Rayleigh-Jean's law
• B. Wein's displacement law
• C. Stefan's law
• D. Planck's quantum law

Explanation: The statement that "radiations are always emitted or absorbed in the form of packets of energy" is a fundamental principle of quantum…

• A. Rayleigh
• B. Wein
• C. Einstein
• D. Max Planck

Explanation: In 1900, Max Planck proposed a formula that explained in detail the shape of the blackbody spectrum for all wavelengths.

• A. Faraday
• B. Newton
• C. Einstein
• D. Planck

Explanation: Quantum theory of radiation was significantly developed by Albert Einstein.