JEE Main202330 Jan 2023Morning ShiftPhysicsDual Nature of MatterActual
A point source of light is placed at the centre of curvature of a hemispherical surface. The source emits a power of 24 W . The radius of curvature of hemisphere is 10 cm and the inner surface is completely reflecting. The force on the hemisphere due to the light falling on it is ______ × 10 - 8 N .
Correct answer
0
Step-by-step solution
For completely reflecting surface, force, F = 2 I A c , where, I = P Surface   area is intensity of radiation, A is surface area and c is speed of light. F = 2 I c π R 2 = 2 P 0 4 π R 2 π R 2 c = P 0 2 c = 24 2 × 3 × 10 8 = 4 × 10 - 8   N