Free Dawn of Modern Physics MCQs with Answers

• A. 7.3 x 10^11 m
• B. 7.3 x 10^8 m
• C. 7.3 x 10^-11 m
• D. 7.3 x 10^-13 m

Explanation: De broglie wavelength of any particle: λ = h/p and p = mv ∴λ = h/mvλ = 6.6* 10-34 / (9.1*10-31*1.0*107)λ= 7.2527473e-11m

• A. 0.3 x 10^-19J
• B. 3 x 10^-19J
• C. 30 x 10^-19J
• D. 300 x 10^-19J

Explanation: Using the Formula E=hc/λ 6.63 x 10-34 x 3.0 x 108/6600 x 10-10 = 3.01x10-19 J

• A. Photoelectric effect
• B. Compton effect
• C. Photoluminescence
• D. None of these options is correct

Explanation: The photoelectric cell, photocell, or photovoltaic cell works on the principle of photoelectric effect.

• A. Inertia
• B. Wave nature
• C. Angular momentum
• D. Linear momentum

Explanation: Correct option is C.Planck's constant is analogous to angular momentum.Furthermore, angular momentum has the same units as linear momentum…

• A. 180°
• B. None
• C. 0°
• D. 90°

Explanation: Compton shift is maximum at θ = π = 180 because the photon loses the maximum amount of energy to the motion of the electron.

• A. Wavelength of light
• B. Frequency
• C. Voltage of source
• D. Intensity of light

Explanation: Einstein's Photoelectric Effect equation is: hf = hfo + KEmax Where hf is the energy of the photon, hfo is the work function of the…

• A. Beta rays
• B. Gamma rays
• C. X-rays
• D. All of these

Explanation: The photoelectric effect is exhibited when a material absorbs electromagnetic radiation and electrons are emitted.

• A. 1/4
• B. 0
• C. 1/2
• D. 1

Explanation: Photons carry spin-1, whereas electrons, protons, neutrons, and quarks carry spin-1/2.

• A. Fe
• B. MgO
• C. I
• D. ZnS

Explanation: Anode ray produces fluorescence when strikes on Zinc Sulphide Screen whereas Cathode ray produces fluorescence when strikes on Soda-glass…

• A. Compton effect
• B. Quantum theory
• C. Photoelectric effect
• D. Pair production

Explanation: Einstein was awarded a Nobel prize for his work in the photoelectric effect.

• A. Line
• B. Continous
• C. Band
• D. All of these

Explanation: A spectrum appearing uninterrupted by lines or bands across a range of wavelengths is called a continuous spectrum.The spectrum from black…

• A. Temperature
• B. Frequency
• C. Wave length
• D. None of the above

Explanation: The energy of a photon is given by the equation:E = hfwhere E is the energy of the photon, h is Planck's constant, and f is the frequency…

• A. Zero
• B. hλ
• C. λ/h
• D. h/λ

Explanation: The momentum of a photon, p, measured in kilogram meters per second, is equal to Planck's constant, h, divided by the de Broglie…

• A. Fast moving electron
• B. Slow moving electron
• C. Eectron at rest
• D. None of these

Explanation: The correct answer is Option A: A beta particle is actually a fast-moving electron.

• A. Electric in nature
• B. Magnetic in nature
• C. Both A & B
• D. None of these

Explanation: Polarization explains that light is an electromagnetic wave and has both electric and magnetic components.

• A. Blue
• B. White
• C. Purple
• D. None of these

Explanation: When light with a sufficiently high-frequency shine on a metal plate like aluminum, electrons are ejected from the plate.

• A. λ=h x p
• B. λ= h/p
• C. λ= h+p
• D. λ= h-p

Explanation: The de Broglie expression is λ=h/p, where λ is the wavelength, h is Planck's constant, and p is the momentum of the particle.So the answer…

• A. Rough white surface
• B. Polished white surface
• C. Rough black surface
• D. Polished black surface

Explanation: The key factor in determining how fast a surface releases heat is its ability to absorb light.

• A. Studying rotation of moon and sun
• B. Using interferometer
• C. Using a rotating plane mirror
• D. Using an octagonal rotating mirror D

Explanation: Michelson determined the velocity of light using an experiment known as the Michelson-Morley experiment, which involved an…

• A. Mass
• B. Energy
• C. Intensity
• D. None of these

Explanation: When two photons interact in the same direction, the intensity of the resulting light may change.