Question

The ratio of the angle of deviation produced by a thin prism, when it is placed in air to the angle of deviation produced when it is immersed in water of refractive index $\frac{4}{3}$ is: (Take refractive index of glass $= \frac{3}{2}$)}

• A. $1:4$
• B. $9:8$
• C. $4:1$
• D. $8:9$

Hint:

For a standard glass prism ($\mu = 1.5$) dipped in water ($\mu = 1.33$), the angle of deviation always drops to exactly one-fourth of its original value in air ($\delta_{\text{water}} = \frac{\delta_{\text{air}}}{4}$). Remembering this common factor saves calculation steps!

Answer 1

The Correct Option is C