Free Photons and the Particle Model of Light MCQs with Answers

196 Photons and the Particle Model of Light MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

The particle model treats light as photons with energy E equals hf and momentum related to wavelength. Questions involve the photoelectric effect, work function, threshold frequency, stopping potential and photon energy, while distinguishing particle behaviour from the wave description of interference and diffraction.

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196 questions · page 10 of 10

  • A. Pair production
  • B. Compton effect
  • C. Annihilation of matter
  • D. photoelectric effect

Explanation: A.The creation of an elementary particle and its antiparticle, usually when a photon (or another neutral boson) interacts with a nucleus…

Correct answer: Annihilation of matter
  • A. Intensity of the incident light
  • B. Frequency of the incident light
  • C. Temperature of the photosensitive surface
  • D. None of the above

Explanation: The maximum KE of emitted photoelectrons depends on the frequency of incident lightThis can be represented by the photoelectric equationEk…

Correct answer: Frequency of the incident light
  • A. Intensity of light
  • B. Frequency of light
  • C. Wavelength of light
  • D. Speed of light

Explanation: According to Planck's quantum theory, the intensity of the incident beam is directly related to the number of photons in the beam.

Correct answer: Intensity of light
  • A. E = 0.52 Mev
  • B. E < 1.02 Mev
  • C. E < 0.52 Mev
  • D. E > 1.02 Mev

Explanation: Pair production is a process in which a photon interacts with a nucleus or an atomic electron and produces an electron-positron pair.

Correct answer: E > 1.02 Mev
  • A. Doubled
  • B. More than double
  • C. Unchanged
  • D. Less than double

Explanation: More than double: From Einstein's equation for photoelectric effect , the maximum kinetic energy , K=hν−W where ν= frequency of incident…

Correct answer: More than double
  • A. Max Planck
  • B. Compton
  • C. Lousie
  • D. Einstein

Explanation: Albert Einstein was awarded the Noble Prize in Physics in 1921 for his explanation of the photoelectric effect, which he published in…

Correct answer: Einstein
  • A. 0=90°
  • B. 0=0"
  • C. 0=45°
  • D. 0=180°

Explanation: COMPTON'S EFFECT: It is the scattering of a high-frequency photon after a collision with an electron, which results in a decrease in the…

Correct answer: 0=90°
  • A. The photon's frequency only
  • B. The metal work function and photon's frequency
  • C. The intensity of incident light
  • D. None of the above

Explanation: The maximum kinetic energy of an electron ejected from a metal by a photon is calculated using the equation K_max = hf - φ, where h is…

Correct answer: The metal work function and photon's frequency
  • A. Critical frequency
  • B. Threshold frequency
  • C. Work function
  • D. None of the above

Explanation: This minimum frequency is also called the threshold frequency, and the value of ν0 \nu, start subscript, 0, end subscript depends on the…

Correct answer: Threshold frequency
  • A. v = f.λ
  • B. λ = h / mv
  • C. s = d/t
  • D. p = λ x h

Explanation: The correct formula to calculate the wavelength of an electron is λ = h / mv, known as De Broglie's wave equation.

Correct answer: λ = h / mv
  • A. Blue light
  • B. Yellow light
  • C. X-rays
  • D. Radio wave

Explanation: According to the de Broglie equation, wavelength and momentum are inversely proportional.

Correct answer: X-rays
  • A. 00
  • B. 450
  • C. 900
  • D. 1800

Explanation: The largest change in wavelength occurs when the photon is scattered through 180 degrees because the photon is reflected directly back in…

Correct answer: 1800
  • A. Increase in intensity of light
  • B. Increase in wavelength of light
  • C. Increase in frequency of light
  • D. Never

Explanation: The correct answer is that the number of ejected photoelectrons increases with an increase in the intensity of light.

Correct answer: Increase in intensity of light
  • A. Stopping potential
  • B. Maximum kinetic energy of Photoelectron
  • C. Photoelectric current
  • D. Both (A) & (B)

Explanation: If the frequency of the incident radiation in the photoelectric effect is increased beyond the threshold frequency, it will affect the…

Correct answer: Stopping potential
  • A. The number of photons
  • B. The energy of each photon
  • C. The speed of the photons
  • D. The frequency of photons

Explanation: Einstein proposed the idea that light is quantized into discrete packets of energy called photons.

Correct answer: The number of photons
  • A. Compton effect
  • B. Photoelectric effect
  • C. Pair production
  • D. Pair Annihilation

Explanation: Pair production is the process in which a photon interacts with a nucleus and produces an electron-positron pair.

Correct answer: Photoelectric effect