✓ Board-verified
Physics · 2022 · 3 marks
CBSE 2022 · Region 1 · Set 3 · Q11
For a glass prism of refractive index √ 3, the value of angle of minimum deviation δ is equal to the angle of prism A. Find the angle of prism A. How…
For a glass prism of refractive index $\displaystyle \sqrt{3}$, the value of angle of minimum deviation $\displaystyle \delta$ is equal to the angle of prism A. Find the angle of prism A. How will the angle $\displaystyle \delta$ be affected if the prism were immersed in water ?
Marking-scheme solution
Calculation of Angle of prism & $\displaystyle 2$
Effect of water on prism & $\displaystyle 1$$$\begin{gathered}
\mu=\sqrt{3} \\
\mu=\frac{\sin \dfrac{\left(A+\delta_{m}\right)}{2}}{\sin (A / 2)}
\end{gathered}
$$
$\displaystyle \delta=A$
$\displaystyle \sqrt{3}=\frac{\sin \dfrac{(A+A)}{2}}{\sin (A / 2)}=\frac{\sin A}{\sin \dfrac{A}{2}}$
$\displaystyle \sqrt{3}=\frac{2 \sin \dfrac{A}{2} \cos \dfrac{A}{2}}{\sin \dfrac{A}{2}}=2 \cos \frac{A}{2}$
$\displaystyle \frac{\sqrt{3}}{2}=\cos \frac{A}{2}$
$\displaystyle \therefore A=60^{\circ}$
With increase in refractive index of surrounding medium, angle of deviation $\displaystyle \left(\delta_{\mathrm{m}}\right)$ will decrease
All Ray Optics and Optical Instruments questions2022 question paperNCERT solutions: Ray Optics and Optical InstrumentsPractice Ray Optics and Optical Instruments →
More from Ray Optics and Optical Instruments
- A small bulb is placed at the bottom of a tank, containing a transparent liquid of refractive index √2, to a depth of 1 m. Calculate the area of the…2026
- Assertion: A convex lens, when immersed in a liquid, disappears. Reason ( R ): The refractive indices of material of the lens and the liquid are…2024
- A right angled isosceles glass prism ABC is kept in contact with an equilateral triangular prism DBC as shown in the figure. Both prisms are made of…2025
- A convex lens (n = 1.52) has a focal length of 15.0 cm in air. Find its focal length when it is immersed in liquid of refractive index 1.65. What…2024
- (i) Draw a labelled ray diagram showing the formation of the image at infinity by an astronomical telescope. (ii) A telescope consists of an…2022
- Two convex lenses A and B, each of focal length 10.0 cm, are mounted on an optical bench at 50.0 cm and 70.0 cm respectively. An object is mounted at…2025
- A right-angled prism ABC (refractive index √2 ) is kept on a plane mirror as shown in the figure. A ray of light is incident normally on the face AC.…2025
- A ray of light is incident on a glass prism of refractive index μ and refracting angle A. If it just suffers total internal reflection at the other…2023
CBSE Class 12 Physics past-paper question from the 2022 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.