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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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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The ratio of wavelengths of proton and deuteron accelerated by potential \(V_{p}\) and \(V_{d}\) is \(1:\sqrt2.\) Then, the ratio of \(V_{p}\) to \(V_{d}\) will be:
1. \(1:1\)
2. \(\sqrt 2: 1\)
3. \(2:1\) 
4. \(4:1\) 
Subtopic:  De-broglie Wavelength |
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A nucleus of mass \(M,\) initially at rest, splits into two fragments with masses \(\dfrac{M'}{ 3}\) and \(\dfrac{2M'} { 3}\) \((M'<M).\) The ratio of the de-Broglie wavelengths of the two fragments is:
1. \(1:2\) 2. \(2:1\)
3. \(1:1\) 4. \(2:3\)
Subtopic:  De-broglie Wavelength |
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Let \(K_{1}\) and \(K_{2}\) be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength \(\lambda_1\) and \(\lambda_2\), respectively, are incident on a metallic surface. If \(\lambda_1 = 3 \lambda_2,\) then:
1. \(K_1>\dfrac{K_2}{3} \) 2. \({K}_1<\dfrac{{K}_2}{3} \)
3. \({K}_1=\dfrac{{K}_2}{3} \) 4. \({K}_2=\dfrac{{K}_1}{3}\)
Subtopic:  Einstein's Photoelectric Equation |
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A photon of energy \(10.2\) eV corresponds to light of wavelength \(\lambda_0\). Due to electron transition from \(n = 2 \) to \(n = 1\) in a hydrogen atom, light of wavelength \(\lambda\) is emitted. If we take into account the recoil of atom when photon is emitted then: 
 
1. \(\lambda = \lambda_0\)
2. \(\lambda < \lambda_0\)
3. \(\lambda > \lambda_0\)
4. data is not sufficient to reach a conclusion 
Subtopic:  Photoelectric Effect: Experiment |
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\(A\) and \(B\) are two metals with threshold frequencies \(1.8\times 10^{14}\ \) Hz and \(2.2\times 10^{14}\ \) Hz. Two identical photons of energy \(0.825\) eV each are incident on them. Then, photoelectrons are emitted in:
(Take \(h=6.6\times 10^{-34}\ \) J-s)
1. \(B\) only
2. \(A\) only
3. neither \(A\) nor \(B\)
4. both \(A\) and \(B\)
Subtopic:  Photoelectric Effect: Experiment |
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Photoelectrons emerging from a photocathode (work function: \(2.2~\text{eV}\)) are allowed to fall onto a gas containing hydrogen atoms in the ground state and the first excited state. What is the minimum energy of the photons incident on the photo-cathode that will cause the photoelectrons to transfer energy to the \(\mathrm{H\text-}\)atoms?
1. \(13.6~\text{eV}+2.2~\text{eV}\)
2. \((10.2+2.2)~\text{eV}\)
3. \((3.4+2.2)~\text{eV}\)
4. \((1.89+2.2)~\text{eV}\)
Subtopic:  Photoelectric Effect: Experiment |
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A metallic ball (work function: \(2\) eV) is irradiated with light consisting of photons of wavelength \(200\) nm. The ball has an initial charge, giving it a potential \(1\) V. Take the product of Planck's constant and velocity of light, hc as \(1240\) eV-nm. The final potential of the ball, when photoemission practically stops, is: 
1. \(2\)
2. \(3.2\)
3. \(4.2\)
4. \(5.2\) V
Subtopic:  Photoelectric Effect: Experiment |
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Photons of light of wavelength, \(\lambda=400\) nm are incident on a composite photocathode consisting of multiple regions with metals having work functions of \(2.1\) eV and \(1.1\) eV. The emitted photoelectrons are sent through a retarding potential difference, \(V_0\). What is the minimum value of \(V_0\) required to stop all electrons? (take: \(hc=1240\) eV-nm)
1. \(1\) V 2. \(1.5\) V
3. \(2\) V 4. \(5.2\) V
Subtopic:  Einstein's Photoelectric Equation |
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