Q 12-08-059JEE MainJEE Main 2024 (27 Jan, Shift 2)Medium
An object is placed in a medium of refractive index 3. An electromagnetic wave of intensity $6\times10^8\ \text{W m}^{-2}$ falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space $= 3\times10^8\ \text{m s}^{-1}$):
Answer: (C) $6\ \text{N m}^{-2}$
Speed of light in the medium: $v = \dfrac{c}{n} = 10^8\ \text{m s}^{-1}$.
For complete absorption the radiation pressure is
$$P = \frac{I}{v} = \frac{6\times10^8}{10^8} = 6\ \text{N m}^{-2}$$
Solution by Sreeraj P, M.Sc Physics