A 5 W emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved 1.0 m away, the number of photoelectrons liberated is reduced by a factor of?
1. 4
2. 8
3.16
4. 2
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. |
Consider a beam of electrons (each electron with energy \(E_0\)) incident on a metal surface kept in an evacuated chamber. Then:
1. | no electrons will be emitted as only photons can emit electrons. |
2. | electrons can be emitted but all with energy, \(E_0\) |
3. | electrons can be emitted with any energy, with a maximum of \(\mathrm{E}_0-\phi\) (\(\phi\) is the work function). |
4. | electrons can be emitted with any energy, with a maximum \(E_0\). |