A hydrogen atom \((\mathrm{H})\) and a helium \((\mathrm{He})\) atom, both have the same kinetic energy (they are non-relativistic). Their de-Broglie wavelengths are in the ratio: \(\Large\frac{\lambda_\mathrm{H}}{\lambda_{\mathrm{He}}}=\)
1. \(4\) 2. \(\dfrac14\)
3. \(2\) 4. \(\dfrac12\)

Subtopic:  De-broglie Wavelength |
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In an experiment on the photoelectric effect, the maximum kinetic energy of the emitted electrons is plotted as a function of the frequency of incident radiation. The graph is:
1. a straight line with a positive intercept on the \(x\)-axis (frequency)
2. a straight line with a positive intercept on the \(y\)-axis (kinetic energy)
3. a parabola
4. a hyperbola
Subtopic:  Photoelectric Effect: Experiment |
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Which, of the following, shows the correct graph of the de-Broglie wavelength \((\lambda)\) of a particle and its kinetic energy \((E_K)?\)
1. 2.
3. 4.
Subtopic:  De-broglie Wavelength |
 79%
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Select the correct option based on the statements given below:
Statement I:  By de-Broglie's hypothesis momentum of an electron, \(p=h/ \lambda\).
Statement II: The energy of an electron is given by; \(E=hc/ \lambda\).
1. Statement I is correct and Statement II is incorrect.
2. Statement I is incorrect and Statement II is correct.
3. Both Statement I and Statement II are correct.
4. Both Statement I and Statement II are incorrect.
Subtopic:  De-broglie Wavelength |
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Photons and electrons of the same wavelength are compared. Which one carries larger momentum?
1. photon
2. electron
3. neither, since both have equal momenta
4. it could be either, depending on the energy
Subtopic:  De-broglie Wavelength |
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The de-Broglie wavelength of an electron in the ground state of a \(\mathrm H\text -\)atom is \(\lambda_1\) and that on the \(\mathrm{He}^{+}\text -\)ion is \(\lambda_2.\) The kinetic energies of the electrons in the \(\mathrm H\text -\)atom and the \(\mathrm{He}^{+}\text -\)ion-having the same de-Broglie wavelength are \(E_1\) and \(E_2.\) The ratio \(\dfrac{\lambda_1}{\lambda_2}\) is:
1. \(4\)

2. \(2\)

3. \(\dfrac12\)

4. \(\dfrac14\)
Subtopic:  De-broglie Wavelength |
 55%
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Light of wavelength \(4000~\mathring{A}\) is incident on a metal whose work function is \(2.0\) eV. The fastest photo-electrons emitted have an energy of:
(Take \(hc=12400\) eV-\(\mathring A\))
1. \(0.5\) eV
2. \(3.1\) eV
3. \(1.1\) eV
4. \(2\) eV
Subtopic:  Einstein's Photoelectric Equation |
 83%
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The de-Broglie wavelength of a photon of energy \(E\) is \(\lambda_{ph}\) and that of an electron (non-relativistic) of the same energy \(E\) is \(\lambda_{e}.\) Then (assume \(E\text ~\)few \(e\text{V}\)):
1. \(\lambda_{ph}=\lambda_e\)
2. \(\lambda_{ph}<\lambda_e\)
3. \(\lambda_{ph}>\lambda_e\)
4. any of the above may be true
Subtopic:  De-broglie Wavelength |
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Match the following items in Column-I with their corresponding descriptions in Column-II:
Column-I Column-II
\(\mathrm{(A)}\) Radiation pressure \(\mathrm{(I)}\) Particle nature of radiation
\(\mathrm{(B)}\) Threshold wavelength \(\mathrm{(II)}\) Stopping potential
\(\mathrm{(C)}\) Maximum kinetic energy of photoelectron \(\mathrm{(III)}\) Maximum wavelength of an incident photon in photoelectric effect
\(\mathrm{(D)}\) Quantisation of angular momentum of the electron \(\mathrm{(IV)}\) De-Broglie hypothesis
Codes:
1. \(\mathrm{A\text-I,B\text-III,C\text- II,D\text-IV}\)
2. \(\mathrm{A\text-III,B\text-I,C\text- II,D\text-IV}\)
3. \(\mathrm{A\text-I,B\text- III,C\text-IV,D\text- II}\)
4. \(\mathrm{A\text-IV,B\text-II,C\text-I,D\text-III}\)
Subtopic:  Particle Nature of Light |
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The de-Broglie wavelength of the electron accelerated through a potential difference \(V\) equals the de-Broglie wavelength of an electron in the ground state of the hydrogen atom. The value of \(V\) is:
1. \(13.6\) volts
2. \(27.2\) volts
3. \(10.2\) volts
4. \(6.8\) volts
Subtopic:  De-broglie Wavelength |
 76%
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