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 9 of 10
- A. 0.25 V
- B. 0.5 V
- C. 1.0 V
- D. 2.0 V
Explanation: The stopping potential in a photocell is related to the intensity of light falling on it.
Correct answer: 0.25 V- A. Intensity of incident light.
- B. Nature of emitter material.
- C. Frequency of incident light.
- D. Potential difference in the power source.
Explanation: The correct answer is the intensity of incident light. The work function is a property of the material and is related to the minimum…
Correct answer: Intensity of incident light.- A. Infinite
- B. Zero
- C. Negative
- D. Still not found
Explanation: The angular momentum of a photon is zero. A photon is a massless particle, and angular momentum is defined as the product of the moment of…
Correct answer: Zero- A. Structure of metals only
- B. Nature of surface only
- C. Both metals and nature of surface
- D. Threshold frequency
Explanation: Work functions depend on the 'structure' and 'chemical composition of a surface'.
Correct answer: Both metals and nature of surface- A. 0, 0
- B. 1+, 0
- C. 1-, 0
- D. 1, 1
Explanation: A photon is massless, has no electric charge, and is a stable particle.
Correct answer: 0, 0- A. 0.01eV sm-1
- B. 0.001eV s m-1
- C. 0.03eV s m-1
- D. 0.04eV s m-1
Explanation: Energy of photon, E=3MeV=3×10^6eVLinear momentum of the photon, p=E/cwhere c is the speed of light in vacuum p= 3×10^6 eV / 3×10^8…
Correct answer: 0.01eV sm-1- A. Momentum
- B. Frequency
- C. Mass
- D. All of these options are correct
Explanation: In quantum physics, wave-particle duality states that any particle or quantum phenomenon can be represented as either a particle or a…
Correct answer: Mass- A. Remain constant
- B. Increase
- C. Decrease
- D. None of these
Explanation: The energy of photons is directly proportional to their frequency and inversely proportional to their wavelength, so lower-energy photons…
Correct answer: Decrease- A. Infinite rest mass
- B. Rest mass but no charge
- C. No rest mass & no charge
- D. A & C are correct
Explanation: A photon is simply a quantized particle of light and so has no rest mass nor charge.
Correct answer: No rest mass & no charge- A. 5 x 10^14 Hz
- B. 6 x 10^14Hz
- C. 7 x 10(14) Hz
- D. 9 x 10(14) Hz
Explanation: v=f λf= v/λ = 3x10^8/500 x 10^-9 = 6x10^(14) Hz
Correct answer: 6 x 10^14Hz- A. Emitted
- B. Absorbed
- C. Travelling
- D. All of these
Explanation: Since an X-ray photon has a large momentum (by the de Broglie relation), its uncertainty in momentum is low, but the uncertainty of…
Correct answer: All of these- A. Increase.
- B. Completely diminishes.
- C. Reduces to half.
- D. Remains unchanged.
Explanation: The requirement for a photon to carry out pair production is a minimum energy level of 1.02 MeV, if the energy level increases the…
Correct answer: Increase.- A. Infrared.
- B. Ultraviolet.
- C. Visible.
- D. Green.
Explanation: In photocell cesium, coated oxidised silver cathode emits electrons for infrared light.
Correct answer: Infrared.- A. Low
- B. High
- C. Intermediate
- D. Both A and C
Explanation: Energy will be emitted when electrons jump from higher energy levels to lower energy levels.
Correct answer: High- A. hf - ϕ = ½ mv2
- B. E = hc2
- C. E = mc2
- D. hf = ½ mv2
Explanation: Explanation:Einstein's photoelectric equation states that the maximum energy of a photoelectron is equal to the difference between the…
Correct answer: hf - ϕ = ½ mv2- A. 1.43 x 10^-11 m
- B. 2.43 x 10^-12 m
- C. 2.56 x 10^-12 m
- D. 3.46 x 10^-6 m
Explanation: Explanation: This value is a constant and is given as: = h / moc = 6.63 × 10-23 / (9.1093837015 × 10-31kg) (3× 108 ms-1) = 2.43 × 10-12m
Correct answer: 2.43 x 10^-12 m- A. Compton Effect
- B. Photoelectric Effect
- C. Nuclear Effect
- D. Pair Production
Explanation: Explanation:For intermediate energy of radiations, the dormant process is Compton effect. This option is not correct.
Correct answer: Compton Effect- A. High frequency
- B. Low frequency
- C. Threshold frequency
- D. Resonance frequency
Explanation: The correct answer is Threshold frequency. This is the minimum frequency of light necessary to eject electrons from a metal surface as…
Correct answer: Threshold frequency- A. α-particle
- B. β-particle
- C. X-rays
- D. γ-radiations
Explanation: In pair production, a high-energy photon interacts with a nucleus to transform into a particle and its antiparticle, such as an electron…
Correct answer: γ-radiations- A. 2.00 x 10^16Hz
- B. 2.00 x 10^14 Hz
- C. 5.00 x 10^16Hz
- D. 2.00 x 10^18 Hz
Explanation: Where h is planck's constant whose value is 6.6x10^-34J.s = 6.6x10^-34/4.42x10^-26 =1.5x10^-8m Now finding frequency of photon: 𝞴xf=c c…
Correct answer: 2.00 x 10^16Hz