NEET2009PhysicsThermal Properties of MatterActual
Light with an energy flux of 18 ~W / cm ^2 falls on a non-reflecting surface at normal incidence. The pressure exerted on the surface is
Options
- A2 ~N / m ^2
- B2 10⁻⁴ ~N / m ^2
- C6 ~N / m ^2
- D6 10⁻⁴ ~N / m ^2
Correct answer
D. 6 10⁻⁴ ~N / m ^2
Step-by-step solution
Radiation pressure P_ rad due to light falling on a non-reflecting surface at normal incidence is given by aligned & P_ rad = Energy flux Speed of light = 18 ~W / cm ^2 3 10^8 ~m / s & = 18 10^4 ~W / m ^2 3 10^8 ~m / s =6 10⁻⁴ ~N / m ^2 aligned