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Q. No.On two metal surfaces, a monochromatic light of 6 eV was incident. They have ratio of their work function and maximum KE as
\(\frac{\phi_1}{\phi_2}=\frac{1}{2}, \frac{\left(\mathrm{KE}_{\max }\right)_1}{\left(\mathrm{KE}_{\max }\right)_2}=\frac{2.62}{1}\)
Then \(\phi_1\) and \(\phi_2\) values are respectively (in eV):
1. 2.292, 4.584
2. 4.584, 2.292
3. 4.584, 9.168
4. 1.146, 2.292
\(\frac{\phi_1}{\phi_2}=\frac{1}{2}, \frac{\left(\mathrm{KE}_{\max }\right)_1}{\left(\mathrm{KE}_{\max }\right)_2}=\frac{2.62}{1}\)
Then \(\phi_1\) and \(\phi_2\) values are respectively (in eV):
1. 2.292, 4.584
2. 4.584, 2.292
3. 4.584, 9.168
4. 1.146, 2.292
Subtopic: Photo Electric Effect | Electromagnetic Radiation |
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Level 2: 60%+
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Consider the following statements:
| Statement I: | The number of emitted photoelectrons increases with increase in the frequency of incident light. |
| Statement II: | The kinetic energy of emitted photoelectrons increases with increase in the frequency of incident light. |
| 1. | Statement I is true but Statement II is false. |
| 2. | Statement I is false but Statement II is true. |
| 3. | Both Statement I and Statement II are true. |
| 4. | Both Statement I and Statement II are false. |
Subtopic: Photo Electric Effect |
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Level 2: 60%+
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If work function is \(6.6~\text{eV}.\) The threshold frequency is \(\text{x}\times 10^{14} \text{Hz},\) Find \(\text{x}.\) \((\text{h}=6.6\times10^{-34} ~\text{J.S})\)
1. 18
2. 16
3. 21
4. 25
1. 18
2. 16
3. 21
4. 25
Subtopic: Photo Electric Effect |
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Level 1: 80%+
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Two metals are given:
Metal – 1: Work function = 4.8 eV
Metal – 2: Work function = 2.8 eV
Photons of wavelength 350 nm are incident on both metals separately. Which metal will eject electrons at this wavelength?
1. Metal-1 only
2. Metal-2 only
3. Both metal -1 and metal -2
4. None of metal -1 and metal -2
Metal – 1: Work function = 4.8 eV
Metal – 2: Work function = 2.8 eV
Photons of wavelength 350 nm are incident on both metals separately. Which metal will eject electrons at this wavelength?
1. Metal-1 only
2. Metal-2 only
3. Both metal -1 and metal -2
4. None of metal -1 and metal -2
Subtopic: Photo Electric Effect |
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Level 2: 60%+
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The threshold frequency of a metal is \(1.4 \times 10^{15}sec^{-1}\). Calculate the minimum energy required to eject a photoelectron from this metal.
[Given: Planck’s constant, \(h = 6.6 \times 10^{-34} J sec\)]
2. \(9.24 \times 10^{-18}J \)
3. \(4.62 \times 10^{-19}J \)
4. \(4.62 \times 10^{-18}J \)
Subtopic: Photo Electric Effect |
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Level 1: 80%+
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The energy of one mole of photons of radiation of wavelength \(300~\text{nm}\) is (Given \(\text{h}=6.63\times10^{-34}\text{Js, N}_A=6.02\times10^{23}\text{mol}^{-1},\text{c}=3\times10^8 \text{ms}^{-1})\)
1. \(235~\text{kJ mol}^{-1}\)
2. \(325~\text{kJ mol}^{-1}\)
3. \(399~\text{kJ mol}^{-1}\)
4. \(435~\text{kJ mol}^{-1}\)
1. \(235~\text{kJ mol}^{-1}\)
2. \(325~\text{kJ mol}^{-1}\)
3. \(399~\text{kJ mol}^{-1}\)
4. \(435~\text{kJ mol}^{-1}\)
Subtopic: Photo Electric Effect |
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Level 1: 80%+
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Determine the minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal:
[Given: The threshold frequency of platinum is \(1.3\times10^{15}\text{s}^{-1}\) and \(\text{h}=6.6\times10^{-34}~\text{Js}.]\)
[Given: The threshold frequency of platinum is \(1.3\times10^{15}\text{s}^{-1}\) and \(\text{h}=6.6\times10^{-34}~\text{Js}.]\)
| 1. | \(3.21\times 10^{-14}~\text{J}\) | 2. | \(6.24\times 10^{-16}~\text{J}\) |
| 3. | \(8.58\times 10^{-19}~\text{J}\) | 4. | \(9.76\times 10^{-20}~\text{J}\) |
Subtopic: Photo Electric Effect |
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Level 1: 80%+
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A source of monochromatic radiation of wavelength \(400~ nm\) provides \(1000 ~J\) of energy in \(10\) seconds. When this radiation falls on the surface of sodium, \(x\times 10^{20}\) electrons are ejected per second. Assume that wavelength \(400 ~nm\) is sufficient for ejection of electron from the surface of sodium metal. The value of \(x\) is: (Nearest integer)
[Given: \(h = 6.626 \times 10^{–34}~ Js\)]
1. Four (4)
2. Two (2)
3. Six (6)
4. Eight (8)
[Given: \(h = 6.626 \times 10^{–34}~ Js\)]
1. Four (4)
2. Two (2)
3. Six (6)
4. Eight (8)
Subtopic: Photo Electric Effect |
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Level 2: 60%+
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A photoelectric experiment is conducted using light of wavelength λ. The fastest ejected electron has a momentum of p. If the momentum of the fastest ejected electron is to be increased to 1.5p, what is the new wavelength of the incident light?
(Assume kinetic energy of ejected photoelectron to be very high in comparison to the work function)
1.
2.
3.
4.
Subtopic: Photo Electric Effect |
Level 3: 35%-60%
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