1. | four times, doubled |
2. | doubled, remains unchanged |
3. | remains unchanged, doubled |
4. | four times, remains unchanged |
Which of the following statements about photons is incorrect?
1. | The rest mass of a photon is zero. |
2. | \(h\nu/c.\) | The momentum of a photon is given by
3. | \(h\nu.\) | The energy of a photon is
4. | Photons do not exert any pressure. |
1. | \(\dfrac{3}{2} \nu\) | 2. | \(2\nu\) |
3. | \(3\nu\) | 4. | \(\dfrac{2}{3} \nu\) |
In a photoelectric experiment, blue light is capable of ejecting a photoelectron from a specific metal while green light is not able to eject a photoelectron. Ejection of photoelectrons is also possible using light of the colour:
1. | yellow | 2. | red |
3. | violet | 4. | orange |
Assertion (A): | The work function of aluminium is \(4.2~\text{eV}\). Emission of electrons will not be possible if two photons, each of energy \(2.5~\text{eV}\), strike an electron of aluminium. |
Reason (R): | For photoelectric emission, the energy of each photon should be greater than the work function of aluminium. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | The photoelectric effect demonstrates the wave nature of light. |
Reason (R): | The number of photoelectrons emitted is proportional to the frequency of light. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |