- 1(current)
Q. No.A beam of light of wavelength \(\lambda\) and with illumination \(L\) falls on a clean surface of sodium. If \(N\) photoelectrons are emitted each with kinetic energy \(E\), then:
1. \(N \propto L \) and \(E \propto L \)
2. \(N \propto L \) and \(E \propto \frac{1}{\lambda}\)
3. \(N \propto \lambda\) and \(E \propto L \)
4. \(N \propto \frac{1}{\lambda}\) and \(E \propto \frac{1}{L}\)
Subtopic: Â Electron Emission |
 82%
Level 1: 80%+
Hints
In an inert gas discharge tube, \(2.9\times 10^{18}\) positive ions \((e^+)\) move to the right through a cross-section of the tube every second, while \(1.2\times 10^{18}\) negative ions \((e^-)\) move to the left in the same time. What is the magnitude of the current through the tube?
| 1. | \(0.656~\text A\) | 2. | \(2.384 \times 10^{-3} ~\text A\) |
| 3. | \(2.384 \times 10^{-6} ~\text A\) | 4. | \(2.384 \times 10^{-9} ~\text A\) |
Subtopic: Â Electron Emission |
 77%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
A laser emits monochromatic light with a frequency of \(8 \times 10^{15}~\text{Hz} \) and a power output of \(5 \times 10^{-3}~\text{W}. \) What is the number of photons emitted per second?
1. \(9.5 \times 10^{18} \)
2. \(9.5 \times 10^{14} \)
3. \(3.5 \times 10^{18} \)
4. \(3.5 \times 10^{14} \)
1. \(9.5 \times 10^{18} \)
2. \(9.5 \times 10^{14} \)
3. \(3.5 \times 10^{18} \)
4. \(3.5 \times 10^{14} \)
Subtopic: Â Electron Emission |
 76%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
- 1(current)
Q. No.
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