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प्रश्न
Is it always possible to see the photoelectric effect with a red light?
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उत्तर
No, it is not possible to see the photoelectric effect with a red light.
Explanation:
The energy required to rip an electron out of its orbital is equal to the electron's work function, and photons in red light lack this energy. Because light behaves like particles rather than a continuous stream, even very high-intensity red light will never be able to overcome an electron's work function (in this case), because each photon fails to do so. This demonstrates the particle behaviour of light. The photoelectric effect demonstrates the particle nature of light, and even very intense or prolonged exposure to red light will not cause the effect if the photon energy is insufficient.
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संबंधित प्रश्न
Choose the correct option.
Polychromatic (containing many different frequencies) radiation is used in an experiment on the photoelectric effect. The stopping potential ______.
Using the values of work function given in the following table, tell which metal will require the highest frequency of incident radiation to generate photocurrent.
Typical values of work function for some common metals
| Metal | Work function (in eV) |
| Potassium | 2.3 |
| Sodium | 2.4 |
| Calcium | 2.9 |
| Zinc | 3.6 |
| Silver | 4.3 |
| Aluminium | 4.3 |
| Tungsten | 4.5 |
| Copper | 4.7 |
| Nickel | 5.0 |
| Gold | 5.1 |
The maximum kinetic energy of the photoelectrons depends only on ______
Define photoelectric effect.
State Einstein photoelectric equation.
With the help of a circuit diagram describing an experiment to study the photoelectric effect.
With the help of a circuit diagram describe the experiment to study the characteristics of the photoelectric effect. Hence discuss any 2 characteristics of the photoelectric effect.
The maximum velocity of photoelectron emitted is 4.8 m/s. If the e/m ratio of the electron is 1.76 × 1011 C/kg, then stopping potential is given by ______
Which one of the following is TRUE in photoelectric emission?
Photoelectrons emitted from a metallic surface are initially ____________.
Threshold wavelength for lithium metal is 6250 Å. For photoemission, the wavelength of the incident light must be ______.
The photo electric effect to take place for a metal, the minimum frequency required is 5.792 × 1014 Hz. A light of wavelength 6000 Å is incident on that metal surface. What is the corresponding frequency of light and will there be photoelectric emissions? [velocity of light = 3 × 108 m/s]
Photoelectrons are emitted from a photosensitive surface for the light of wavelengths λ1 = 360 nm and λ2 = 600 nm. What is the ratio of work functions for lights of wavelength 'λ1' to 'λ2'?
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photo-emission from this substance is approximately (h = 6.63 × 10-34 Js)[1eV = 1.6 × 10-19 J]
Following graphs show the variation of stopping potential corresponding to the frequency of incident radiation (F) for a given metal. The correct variation is shown in graph (v0 = Threshold frequency).
A light of wavelength '`lambda`' and intensity 'I' falls on photosensitive material. If 'N' photoelectrons are emitted, each with kinetic energy E, then ____________.
When the work function of a metal increases, maximum kinetic energy of emitted photoelectrons ____________.
In a photoelectric experiment, ultraviolet light of wavelength 280 nm is used with a lithium cathode having work function Φ = 2.5 eV. If the wavelength of incident light is switched to 400 nm, find out the change in the stopping potential.
(h = 6.63 × 10-34 Js, c = 3 × 108 ms-1)
The radiation emitted, when an electron jumps from n = 3 to n = 2 orbit is a hydrogen atom, falls on a metal to produce photoelectron. The electrons from the metal surface with maximum kinetic energy are made to move perpendicular to a magnetic field of `1/320`T in a radius of 10-3m. Find the 320 work function of metal:
We wish to observe an object which is 2.5Å in size. The minimum energy photon that can be used ______.
If the electron in hydrogen atom jumps from second Bohr orbit to ground state and difference between energies of the two states is radiated in the form of photons. If the work function of the material is 4.2 eV, then stopping potential is ______.
[Energy of electron in nth orbit = `-13.6/"n"^2` eV ]
The following graphs show the variation of stopping potential corresponding to the frequency of incident radiation (ν) for a given metal. The correct variation is shown in graph [ν0 = threshold frequency].
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(A) |
(B) |
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(C) |
(D) |
Light of two different frequencies whose photons have energies 1.3 eV and 2.8 eV respectively, successfully illuminate a metallic surface whose work function is 0.8 eV. The ratio of maximum speeds of emitted electrons will be ______.
Give Einstein's explanation of the photoelectric effect.
By increasing the voltage in an electron diffraction tube, the radius of the diffraction rings will ______.
Draw a neat labelled diagram of photo-current as a function of accelerating potential for fixed incident intensity but different incident frequencies for the same emitter material.
