Question

If radiation are incident obliquely on a perfectly reflecting surface then the pressure exerted by radiation on the surface will be:

• A. $2e_0{E}^2$
• B. $\frac{1}{3}{e}_0{E}^2$
• C. $e_0{E}^2$
• D. $\frac{{\epsilon }_0{E}^2}{4}$

Answer 1

The correct option is A $2e_0{E}^2$

$P=\frac{Energy}{Velcoity}=\frac{E}{C}$

Energy density of Em Wave = ${\epsilon }_0{E}^{2}P=\frac{h\upsilon }{fz}P=\frac{h}{z}$

$Pressure=\frac{\Delta P}{\Delta t}$ change in momentum per unit area.

$\Delta P=\frac{2{\epsilon }_0{E}^2}{C}Pressure=\frac{2{\epsilon }_0{E}^2}{C}\times C=2{\epsilon }_0{E}^2$