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Q. No.A proton and an \(\alpha\text-\)particle are accelerated through a potential difference of \(100\) V. What is the ratio of the wavelength associated with the proton to that of the alpha-particle?
1. \(\sqrt{2}:1\)
2. \(2:1\)
3. \(2\sqrt{2}:1\)
4. \(\frac{1}{2\sqrt{2}}:1\)
Subtopic: De-broglie Wavelength |
69%
Level 2: 60%+
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What is the momentum of a photon in an \(X\text-\)ray beam of \(10^{-10}\) meter wavelength?
| 1. | \(1.5 \times 10^{-23}~\text{kg-m/s}\) |
| 2. | \(6.6 \times 10^{-24}~\text{kg-m/s}\) |
| 3. | \(6.6 \times 10^{-44}~\text{kg-m/s}\) |
| 4. | \(2.2 \times 10^{-52}~\text{kg-m/s}\) |
Subtopic: De-broglie Wavelength |
91%
Level 1: 80%+
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The energy of quanta of frequency \(10^{15}~\text{Hz}\) and \(h = 6.6 \times 10^{-34}~\text{J-s}\) will be:
1. \(6.6\times 10^{-19}~\text{J}\)
2. \(6.6\times 10^{-12}~\text{J}\)
3. \(6.6\times 10^{-49}~\text{J}\)
4. \(6.6\times 10^{-41}~\text{J}\)
1. \(6.6\times 10^{-19}~\text{J}\)
2. \(6.6\times 10^{-12}~\text{J}\)
3. \(6.6\times 10^{-49}~\text{J}\)
4. \(6.6\times 10^{-41}~\text{J}\)
Subtopic: Particle Nature of Light |
92%
Level 1: 80%+
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The number of photo-electrons emitted per second from a metal surface increases when:
| 1. | The energy of incident photons increases. | 2. | The frequency of incident light increases. |
| 3. | The wavelength of the incident light increases. | 4. | The intensity of the incident light increases. |
Subtopic: Photoelectric Effect: Experiment |
82%
Level 1: 80%+
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A photon of energy \(3.4~\text{eV}\) is incident on a metal having a work function of \(2~\text{eV}.\) The maximum \(K.E\) of photo-electrons is equal to:
| 1. | \(1.4~\text{eV}\) | 2. | \(1.7~\text{eV}\) |
| 3. | \(5.4~\text{eV}\) | 4. | \(6.8~\text{eV}\) |
Subtopic: Einstein's Photoelectric Equation |
92%
Level 1: 80%+
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The spectrum of radiation \(1.0\times 10^{14}\) Hz is in the infrared region.
The energy of one photon of this in joules will be:
1. \(6.62\times 10^{-48}\)
2. \(6.62\times 10^{-20}\)
3. \(\frac{6.62}{3}\times 10^{-28}\)
4. \(3\times 6.62\times 10^{-28}\)
Subtopic: Particle Nature of Light |
91%
Level 1: 80%+
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A photocell is receiving light from a source placed at a distance of \(1\) m. If the same source is placed at a distance of \(2\) m, then the ejected electron:
| 1. | moves with one-fourth of energy as that of the initial energy. |
| 2. | moves with one-fourth of momentum as that of the initial momentum. |
| 3. | will be half in number. |
| 4. | will be one-fourth in number. |
Subtopic: Electron Emission |
70%
Level 2: 60%+
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The stopping potential for photoelectrons:
| 1. | does not depend on the frequency of the incident light. |
| 2. | does not depend upon the nature of the cathode material. |
| 3. | depends on both the frequency of the incident light and the nature of the cathode material. |
| 4. | depends upon the intensity of the incident light. |
Subtopic: Photoelectric Effect: Experiment |
74%
Level 2: 60%+
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If in a photoelectric experiment, the wavelength of incident radiation is reduced from \(6000~\mathring{A}\) to \(4000~\mathring{A}\), then:
| 1. | The stopping potential will decrease. |
| 2. | The stopping potential will increase. |
| 3. | The kinetic energy of emitted electrons will decrease. |
| 4. | The value of the work function will decrease. |
Subtopic: Photoelectric Effect: Experiment |
76%
Level 2: 60%+
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The stopping potential \(V\) for photoelectric emission from a metal surface is plotted along the \(Y\text-\)axis and the frequency \(\nu\) of incident light along the \(X\text-\)axis. A straight line is obtained as shown in the figure. Planck's constant is given by:
| 1. | the slope of the line. |
| 2. | the product of slope on the line and charge on the electron. |
| 3. | the product of intercept along the \(Y\text-\)axis and mass of the electron. |
| 4. | the product of the slope and mass of the electron. |
Subtopic: Einstein's Photoelectric Equation |
69%
Level 2: 60%+
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