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प्रश्न
When monochromatic light is incident on a surface separating two media, why does the refracted light have the same frequency as that of the incident light?
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उत्तर
The frequency and time period of an electromagnetic wave depends only on the source which produces it. The frequency is independent of the medium through which it travels. But the speed and wavelength depend on the medium through which the wave travels. Because of this, the frequency and time period of sound wave does not change due to change in medium.
संबंधित प्रश्न
When monochromatic light is incident on a surface separating two media, the reflected and refracted light both have the same frequency as the incident frequency.
Two monochromatic rays of light are incident normally on the face AB of an isosceles right-angled prism ABC. The refractive indices of the glass prism for the two rays '1' and '2' are respectively 1.35 and 1.45. Trace the path of these rays after entering the prism.
A monochromatic ray of light falls on a regular prism. What is the relation between the angle of incidence and angle of emergence in the case of minimum deviation?
State the essential conditions for diffraction of light ?
When monochromatic light travels from a rarer to a denser medium, explain the following, giving reasons:
(i) Is the frequency of reflected and refracted light same as the frequency of incident light?
(ii) Does the decrease in speed imply a reduction in the energy carried by light wave?
If a monochromatic source of light is replaced by white light, what change would you observe in the diffraction pattern?
Monochromatic fight of wavelength 198 nm is incident on the surface of a metallic cathode whose work function is 2.5 eV How much potential difference must be applied between the cathode and the anode of a photocell to just stop the photocurrent from flowing?
Assertion(A): The photoelectrons produced by a monochromatic light beam incident on a metal surface have a spread in their kinetic energies.
Reason(R): The energy of electrons emitted from inside the metal surface, is lost in collision with the other atoms in the metal.
A narrow slit is illuminated by a parallel beam of monochromatic light of wavelength λ equal to 6000 Å and the angular width of the central maximum in the resulting diffraction pattern is measured. When the slit is next illuminated by light of wavelength λ’, the angular width decreases by 30%. Calculate the value of the wavelength λ’.
Monochromatic light of wavelength 396 nm is incident on the surface of a metal whose work function is 1.125 eV. Calculate:
- the energy of an incident photon in eV.
- the maximum kinetic energy of photoelectrons in eV.
