The curves (1), (2), (3) and (4) show the variation between the applied potential difference (V) and the photoelectric current (i), at two different intensities of light ( ). In which figure is the correct variation shown?
1. | 2. | ||
3. | 4. |
The value of stopping potential in the following diagram is given by:
1. | – 4 V | 2. | – 3 V |
3. | – 2 V | 4. | – 1 V |
When monochromatic radiation of intensity I falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2I what is the number of emitted electrons and their maximum kinetic energy?
1. | N and 2T | 2. | 2N and T |
3. | 2N and 2T | 4. | N and T |
The figure shows different graphs between stopping potential and frequency (\(\nu\)) for the photosensitive surfaces of cesium, potassium, sodium and lithium. The plots are parallel.
The correct ranking of the targets according to their work function first will be:
1. | (i) > (ii) > (iii) > (iv) |
2. | (i) > (iii) > (ii) > (iv) |
3. | (iv) > (iii) > (ii) > (i) |
4. | (i) = (iii) > (ii) = (iv) |
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. |
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 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. |
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 |
For photoelectric emission from certain metals, the cutoff frequency is \(\nu\). If radiation of frequency \(2\nu\) impinges on the metal plate, the maximum possible velocity of the emitted electron will be:
(\(m\) is the electron mass)
1. | \(\sqrt{\frac{h\nu}{m}}\) | 2. | \(\sqrt{\frac{2h\nu}{m}}\) |
3. | \(2\sqrt{\frac{h\nu}{m}}\) | 4. | \(\sqrt{\frac{h\nu}{2m}}\) |
When monochromatic photons of wavelength \(4000\) Å are incident on the metal plate of work function \(2.1\) eV, what will be the stopping potential for the photocurrent?
1. | \(1\) V | 2. | \(2.1\) V |
3. | \(3.1\) V | 4. | Zero |