Q. No.| 1. | photoelectric effect | 2. | interference |
| 3. | refraction | 4. | polarisation |
A photo-cell is illuminated by a source of light, which is placed at a distance \(d\) from the cell. If the distance becomes \(\dfrac{d}{2}\), then the number of electrons emitted per second will be:
1. same
2. four times
3. two times
4. one-fourth
| 1. | \(5.03\times10^{12}~\text{Hz}\) | 2. | \(6.12\times10^{14}~\text{Hz}\) |
| 3. | \(5.16\times10^{14}~\text{Hz}\) | 4. | \(6.51\times10^{12}~\text{Hz}\) |
The work function of caesium is \(2.14~\text{eV}\). The wavelength of incident light if the photocurrent is brought to zero by a stopping potential of \(0.60~\text{V}\) will be:
1. \(454~\text{nm}\)
2. \(440~\text{nm}\)
3. \(333~\text{nm}\)
4. \(350~\text{nm}\)
What is the de-Broglie wavelength associated with an electron moving at a speed of \(5.4\times10^6~\text{m/s}\)?
| 1. | \(0.244~\text{nm}\) | 2. | \(0.135~\text{nm}\) |
| 3. | \(0.157~\text{nm}\) | 4. | \(0.111~\text{nm}\) |
According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is:
| 1. |  |
2. |  |
| 3. |  |
4. |  |
The wavelength of light in the visible region is about \(550~\text{nm}\) (average wavelength) for yellow-green colour. Three materials with work functions are given as \(Al~(4.28~\text{eV}),\) \(Cu~(4.65~\text{eV})\) and \(Na~(2.75~\text{eV}).\) From which of these photosensitive materials can you build a photoelectric device that operates with visible light?
1. \(Al\)
2. \(Cu\)
3. \(Na\)
4. none of the above
| 1. | \(\dfrac{\lambda_0}{\left(1+\dfrac{e E_0}{m} \dfrac{t}{{v}_0}\right)}\) | 2. | \(\lambda_0\left(1+\dfrac{e E_0 t}{m {v}_0}\right)\) |
| 3. | \(\lambda_0 \) | 4. | \(\lambda_0t\) |
A particle is dropped from a height \(H.\) The de-Broglie wavelength of the particle as a function of height is proportional to:
1. \(H\)
2. \(H^{1/2}\)
3. \(H^{0}\)
4. \(H^{-1/2}\)
Two photons have:
| 1. | equal wavelengths have equal linear momenta. |
| 2. | equal energies have equal linear momenta. |
| 3. | equal frequencies have equal linear momenta. |
| 4. | equal linear momenta have equal wavelengths. |
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