Question

For the oblique incidence and complete absorption, if angle $\theta$ is increased then radiation pressure -

• A. also increases.
• B. decreases.
• C. remains constant.
• D. None of these

Answer 1

The correct option is B decreases.

For the oblique incidence and complete absorption, the radiation pressure is,

$P=\frac{I}{c}{\cos }^2\theta$




For $0^{\circ }\le \theta \le {90}^{\circ }$, the value of $\cos \theta$ decreases as $\theta$ increases.

Therefore, the radiation pressure decreases as angle $\theta$ increases.

​​​​​​​Hence, option $\left(B\right)$ is the correct answer.