CUET Preparation Today
What is the force exerted by a photon of intensity 1.4 kWm–2 if it falls on a perfect absorber of radius 2 metre ? |
2.35 × 10–4 N 108 N 8.35 × 104 N 8.8 × 10–8 N |
2.35 × 10–4 N |
$F_{ex} =\frac{P}{c}=\frac{IA}{c}$ $I = 1.4 × 10^3\, W/m^2$ $A = 4πr^2 = 4 × 3.14 × (2)^2 m^2$ $F_{ex} = 2.35 × 10^{–4} N$ |
