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. |
A photon of energy 3.4 eV is incident on a metal having a work function of 2 eV. The maximum K.E. of photo-electrons is equal to:
1. | 1.4 eV | 2. | 1.7 eV |
3. | 5.4 eV | 4. | 6.8 eV |
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. |
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. |
If in a photoelectric experiment, the wavelength of incident radiation is reduced from 6000 Å to 4000 Å, 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. |
The value of stopping potential in the following diagram is given by:
1. | – 4 V | 2. | – 3 V |
3. | – 2 V | 4. | – 1 V |
The energy of a quanta of frequency Hz and will be:
1.
2.
3.
4.
What is the momentum of a photon in an X-ray beam of 10-10 meter wavelength?
1. | \(1.5 \times 10^{-23} \mathrm{~kg}-\mathrm{m} / \mathrm{sec}\) |
2. | \(6.6 \times 10^{-24} \mathrm{~kg}-\mathrm{m} / \mathrm{sec}\) |
3. | \(6.6 \times 10^{-44} \mathrm{~kg}-\mathrm{m} / \mathrm{sec}\) |
4. | \(2.2 \times 10^{-52} \mathrm{~kg}-\mathrm{m} / \mathrm{sec}\) |
If the following particles are moving at the same velocity, then which among them will have the maximum de-Broglie wavelength?
1. Neutron
2. Proton
3. -particle
4. -particle
A particle which has zero rest mass and non-zero energy and momentum must travel with a speed:
1. | Equal to c, the speed of light in vacuum. |
2. | Greater than c. |
3. | Less than c. |
4. | Tending to infinity. |