✓ Board-verified
Physics · 2023 · 3 marks
CBSE 2023 · Region 5 · Set 2 · Q26
(a) A plane wave-front propagating in a medium of refractive index ' μ_1 ' is incident on a plane surface making an angle of incidence (i). It enters…
A plane wave-front propagating in a medium of refractive index ' $\displaystyle \mu_{1}$ ' is incident on a plane surface making an angle of incidence (i). It enters into a medium of refractive index $\displaystyle \mu_{2}\left(\mu_{2}>\mu_{1}\right)$. Use Huygen's construction of secondary wavelets to trace the retracted wave-front. Hence verify Snell's law of refraction.
Using Huygen's construction, show how a plane wave is reflected from a surface. Hence verify the law of reflection.
Marking-scheme solution
(a)
Tracing the refractive wavefront Verification of Snell's Law of refraction
AB is incident wavefront, incident at an angle i . let \(\displaystyle \tau\) be the time taken by wavefront to travel distance BC.
\(\displaystyle B C=\mathrm{v}_{1} \tau\) where \(\displaystyle \mathrm{v}_{1}\) is speed of wave in medium $\displaystyle 1$
To determine shape of refracted wavefront, we draw a sphere of radius \(\displaystyle \mathrm{v}_{2} \tau\),
More from Wave Optics
- Define 'wavefront' of a light wave. A plane wavefront is refracted from a convex lens. Draw the shape of the refracted wavefront. A plane wave…2025
- A double slit set-up was initially placed in a tank filled with water and the interference pattern was obtained using a laser light. When water is…2025
- The phenomenon of interference is shown by2026
- Assertion: In interference and diffraction of light, light energy reduces in one region producing a dark fringe. It increases in another region and…2024
- Using the Huygens' principle, briefly describe reflection of a plane wavefront from a reflecting surface. Hence, prove the laws of reflection.2025
- Assertion: In a Young's double-slit experiment, interference pattern is not observed when two coherent sources are infinitely close to each other.…2024
- (i) Give any two differences between the interference pattern obtained in Young's double-slit experiment and a diffraction pattern due to a single…2024
- A plane wave-front propagating in a medium of refractive index ' μ_1 ' is incident on a plane surface making an angle of incidence (i). It enters…2023
CBSE Class 12 Physics past-paper question from the 2023 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.