JEE Main202126 Aug 2021Morning ShiftPhysicsElectromagnetic WavesActual
The electric field in a plane electromagnetic wave is given by E → = 200 cos 0 . 5 × 10 3 m - 1 x - 1 . 5 × 10 11 rad s - 1 t V m - 1 j ^ . If this wave falls normally on a perfectly reflecting surface having an area of 100 cm 2 . If the radiation pressure exerted by the E.M. wave on the surface during a 10 min exposure is k 10 9 N m - 2 . Find the value of k
Correct answer
0
Step-by-step solution
E 0 = 200 I = 1 2 ε 0 E 0 2 c Radiation pressure P = 2 l c = 2 c 1 2 ε 0 E 0 2 C = ε 0 E 0 2 P = 8 . 85 × 10 - 12 × 200 2 = 8 . 85 × 10 - 8 × 4 = 354 10 9 S o , k = 354