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प्रश्न
Write the three salient features observed in photoelectric effect which can be explained using this equation.
उत्तर
Salient features observed in photoelectric effect: —
•The stopping potential and hence the maximum kinetic energy of emitted electrons varies linearly with the frequency of incident radiation.
• There exists a minimum cut − off frequency v0, for which the stopping potential is zero.
• Photoelectric emission is instantaneous.
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संबंधित प्रश्न
Calculate the wavelength of radiation emitted when electron in a hydrogen atom jumps from n = `oo` to n = 1.
State clearly how photoelectric equation is obtained using the photon pictu.re of electromagnetic radiation.
Define the term ‘stopping potential’ in relation to photo-electric effect.
Cathode rays are passing through a discharge tube. In the tube, there is ______________ .
The saturation current in a triode valve can be changed by changing _____________ .
A discharge tube contains helium at low pressure. A large potential difference is applied across the tube. Consider a helium atom that has just been ionised due to the detachment of an atomic electron. Find the ratio of the distance travelled by the free electron to that by the positive ion in a short time dt after ionisation.
The saturation current from a thoriated-tungsten cathode at 2000 K is 100 mA. What will be the saturation current for a pure-tungsten cathode of the same surface area operating at the same temperature? The constant A in the Richardson-Dushman equation is 60 × 104 Am −2 K−2 for pure tungsten and 3.0 × 104 Am −2 k−2 for thoriated tungsten. The work function of pure tungsten is 4.5 eV and that of thoriated tungsten is 2.6 eV.
On what factor does the maximum kinetic energy of the photoelectrons in a photo cell depend?
Which of the following proves particle nature of light?
Assertion A: The photoelectric effect does not takes place, if the energy of the incident radiation is less than the work function of a metal.
Reason R: Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal.
