JEE Main 2024 Physics question
Average force exerted on a non-reflecting surface at normal incidence is 2.4 × 10⁻⁴ N. If 360 W/cm² is the light energy flux during span of 1 hour 30 minutes. Then the area of the surface is:
Answer: (B)
Solution
F = IA/c with I = 3.6 × 10⁶ W/m²: A = Fc/I = 2.4 × 10⁻⁴ × 3 × 10⁸/(3.6 × 10⁶) = 0.02 m². (The time span is not needed.)