If \(c\) is the velocity of light in free space, the correct statements about photons among the following are:

\((\mathrm{A})\) The energy of a photon is \(E=h\nu.\)
\((\mathrm{B})\) The velocity of a photon is \(c.\)
\((\mathrm{C})\) The momentum of a photon, \(p={\dfrac{h\nu}{c}}.\)
\((\mathrm{D})\) In a photon-electron collision, both total energy and total momentum are conserved.
\((\mathrm{E})\) Photon possesses a positive electric charge.

Choose the correct answer from the options given below:
1. \(\mathrm {(A), (B), (C)}\) and \((\mathrm {D})\) only
2. \(\mathrm {(A), (C)}\) and \((\mathrm{D})\) only
3. \(\mathrm {(A), (B), (D)}\) and \((\mathrm {E})\) only
4. \((\mathrm{A})\) and \((\mathrm {B})\) only
Subtopic:  Particle Nature of Light |
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From NCERT
NEET - 2024
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The graph which shows the variation of \(\bigg({\dfrac{1}{\lambda^2}}\bigg)\) and its kinetic energy, \(E\) is (where \(\lambda\) is de-Broglie wavelength of a free particle):
1.   2.
3. 4.
Subtopic:  De-broglie Wavelength |
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From NCERT
NEET - 2024
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Radiation of wavelength \(280~\text{nm}\) is used in an experiment of photoelectric effect with cathode of work function, \(2.5~\text{eV}.\) The maximum kinetic energy of the photoelectrons is:
[Take \(h=6.62\times10^{-34}~\text{J s}\) and \(c=3\times10^{8}~\text{ms}^{-1}\)]
1. \(4.4~\text{eV}\) 2. \(7.103\times10^{-15}~\text{J}\)
3. \(1.9~\text{eV}\) 4. \(4.60~\text{eV}\)
Subtopic:  Einstein's Photoelectric Equation |
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From NCERT
NEET - 2024
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Given below are two statements:
Statement I: The de Broglie wavelength associated with a material particle depends on its charge and nature.
Statement II: The wave nature of particles in sub-atomic domain is significant and measurable.
 
In the light of the above statements, choose the most appropriate answer from the options given below:
1. Both Statement I and Statement II are correct.
2. Both Statement I and Statement II are incorrect.
3. Statement I is correct but Statement II is incorrect.
4. Statement I is incorrect but Statement II is correct.
Subtopic:  De-broglie Wavelength |
From NCERT
NEET - 2024
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An electron and an alpha particle are accelerated by the same potential difference. Let \(\lambda_\mathrm{e}\) and \(\lambda_\mathrm{\alpha}\) denote the de-Broglie wavelengths of the electron and the alpha particle, respectively, then:
1. \(\lambda_{\mathrm{e}}>\lambda_{\alpha}\)
2. \(\lambda_{\mathrm{e}}=4\lambda_{\alpha}\)
3. \(\lambda_{\mathrm{e}}=\lambda_{\alpha}\)
4. \(\lambda_{\mathrm{e}}<\lambda_{\alpha}\)
Subtopic:  De-broglie Wavelength |
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From NCERT
NEET - 2024
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If \(\phi\) is the work function of photosensitive material in electron-volts and light of a wavelength of numerical value \(\lambda=\dfrac{{hc}}{{e}}\) metres, is incident on it with energy above its threshold value at an instant then the maximum kinetic energy of the photo-electron ejected by it at that instant is (in SI units): 
(take \(h\) as Plank's constant and \(c\) as the velocity of light in free space)
1. \({e}+2\phi \)
2. \(2{e}-\phi \)
3. \({e}-\phi \)
4. \({e}+\phi \)
Subtopic:  Einstein's Photoelectric Equation |
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From NCERT
NEET - 2024
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The work functions of Caesium \((\mathrm{Cs}).\) Potassium \((\mathrm{K}),\) and Sodium \((\mathrm{Na})\) are \(2.14~\text{eV},\) \(2.30~\text{eV}\) and \(2.75~\text{eV}\) respectively. If incident electromagnetic radiation has an incident energy of \(2.20~\text{eV}.\) which of these photosensitive surfaces may emit photoelectrons?
1. \(\mathrm{Na}\) only 2. \(\mathrm{Cs}\) only
3. Both \(\mathrm{Na}\) and \(\mathrm{K}\) 4. \(\mathrm{K}\) only
Subtopic:  Photoelectric Effect: Experiment |
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From NCERT
NEET - 2023
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The de-Broglie wavelength associated with an electron, accelerated by a potential difference of \(81\) V is given by:
1. \(13.6\) nm
2. \(136\) nm
3. \(1.36\) nm
4. \(0.136\) nm
Subtopic:  De-broglie Wavelength |
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From NCERT
NEET - 2023
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The maximum kinetic energy of the emitted photoelectrons in photoelectric effect is independent of:
1. work function of material
2. intensity of incident radiation
3. frequency of incident radiation
4. wavelength of incident radiation
Subtopic:  Photoelectric Effect: Experiment |
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From NCERT
NEET - 2023
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When two monochromatic lights of frequency, \(\nu\) and \(\dfrac{\nu}{2}\) are incident on a photoelectric metal, their stopping potential becomes \(\dfrac{V_{s}}{2}\) and \(V_s\), respectively. The threshold frequency for this metal is:
1. \(\dfrac{3}{2} \nu\) 2. \(2\nu\)
3. \(3\nu\) 4. \(\dfrac{2}{3} \nu\)
Subtopic:  Einstein's Photoelectric Equation |
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From NCERT
NEET - 2022
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