NEET 2023, Physics Q13: Critical Angle and Total Internal Reflection

NEET2023Physics

Light travels a distance $x$ in time $t_{1}$ in air and $10 x$ in time $t_{2}$ in another denser medium. What is the critical angle for this medium?

Solution

Speed in air $v_{1} = \frac{x}{t _{1}}$ ; speed in medium $v_{2} = \frac{10 x}{t _{2}}$ .

Critical angle satisfies $sin θ_{c} = \frac{v _{2}}{v _{1}} = \frac{10 x / t _{2}}{x / t _{1}} = \frac{10 t _{1}}{t _{2}}$ .

$∴ θ_{c} = sin^{- 1} (\frac{10 t _{1}}{t _{2}})$ .

Concept behind this question

Concept-wise practice with instant solutions on Fundamenthol.