Planck's Quantum Theory

Planck's Quantum Theory MDCAT MCQs with answers

6 past paper MCQs on Planck's Quantum Theory, from the Atomic Structure unit of MDCAT Chemistry. The year each question appeared is shown where known; tap “Show answer” for the correct option and a short solution.

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1.The amount of energy associated with a quantum of radiation is directly proportional to its: (MDCAT 2020)

  1. photon
  2. wavelength
  3. frequency
  4. velocity
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Correct answer: (c) frequency

$E=h

2.According to Planck's quantum theory, if the frequency of photon is doubled, the value of hf will be: (KMU MDCAT 2025)

  1. Doubled
  2. Increased 3 times
  3. Increased 4 times
  4. Unchanged
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Correct answer: (a) Doubled

The energy of a quantum is $hf$, which is proportional to the frequency.

3.Highest energy for one quantum among radiation is: (SZABMU MDCAT 2025)

  1. microwave
  2. infrared
  3. ultra violet
  4. visible
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Correct answer: (c) ultra violet

Energy is $hf$, and of these four the ultraviolet has the highest frequency.

4.The amount of energy associated with quantum of radiation is directly proportional to: (NUMS MDCAT 2023)

  1. Photon
  2. Wavelength
  3. Frequency
  4. Velocity
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Correct answer: (c) Frequency

A quantum carries energy $hf$, proportional to the frequency.

5.What is the value of Planck’s constant {h)? (PMC MDCAT 2022)

  1. 6.62×10^-34Js
  2. 6.02×10^-34Js
  3. 6.62×10^-33Js
  4. 6.34×10^-34 Js
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Correct answer: (a) 6.62×10^-34Js

Planck’s constant is $6.62\times10^{-34}\,\mathrm{J\,s}$.

6.Which is the correct demonstration of de-Broglie equation? (PMC MDCAT 2022)

  1. λ=mv/h
  2. λ=h/mv
  3. h=λ/mv
  4. P=λ/h
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Correct answer: (b) λ=h/mv

De Broglie put the wavelength of a particle at $h/mv$.

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