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प्रश्न
Using Huygens’s construction of secondary wavelets draw a diagram showing the passage of a plane wavefront from a denser to a rarer medium. Using it verifies Snell’s law.
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उत्तर
AB: Incident Plane Wave Front and CE is Refracted Wave Front.
`sini = (BC)/(AC)` and `sinr = (AE)/(AC)`
`(sini)/(sinr) = (BC)/(AE) = v_1/v_2` = constant
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संबंधित प्रश्न
Explain how Corpuscular theory predicts the speed of light in a medium, say, water, to be greater than the speed of light in vacuum. Is the prediction confirmed by experimental determination of the speed of light in water? If not, which alternative picture of light is consistent with the experiment?
A plane wavefront propagating in a medium of refractive index 'μ1' is incident on a plane surface making the angle of incidence 'i' as shown in the figure. It enters into a medium of refractive index 'μ2' (μ2 > μ1). Use Huygens' construction of secondary wavelets to trace the propagation of the refracted wavefront. Hence verify Snell's law of refraction.
The optical properties of a medium are governed by the relative permittivity (εr) and relative permeability (µr). The refractive index is defined as `sqrt(µ_r ε_r) = n`. For ordinary material εr > 0 and µr > 0 and the positive sign is taken for the square root. In 1964, a Russian scientist V. Veselago postulated the existence of material with εr < 0 and µr < 0. Since then such ‘metamaterials’ have been produced in the laboratories and their optical properties studied. For such materials `n = - sqrt(µ_r ε_r)`. As light enters a medium of such refractive index the phases travel away from the direction of propagation.
- According to the description above show that if rays of light enter such a medium from air (refractive index = 1) at an angle θ in 2nd quadrant, them the refracted beam is in the 3rd quadrant.
- Prove that Snell’s law holds for such a medium.
In the refraction construction, which medium is assumed to be denser?
Which expression gives the wavelength of light in medium 1?
Which expression gives the wavelength of light in medium 2?
What happens to the wavelength of light when it goes from a rarer to a denser medium?
How does the speed of light in a denser medium compare with its speed in a rarer medium?
Which picture of light was needed to address why its speed differs between media?
How does the wave picture's conclusion about the speed of light in a denser medium compare with that deduced from the particle picture?
