Question

Radiations of intensity $0.5W/m^2$ are striking a metal plate. The pressure on the plate is

• A. 0.166 X 10^-8 N/m²
• B. 0.332 X 10^-8 N/m²
• C. 0.111 X 10^-8 N/m²
• D. 0.083 X 10^-8 N/m²

Answer 1

The correct option is A 0.166 X 10^-8 N/m²

Intensity or power per unit area of the radiations
$P=fv$
$\Rightarrow f=\frac{P}{v}=\frac{0.5}{3\times {10}^8}=0.166\times {10}^{-8}N/m^2$