Q: The pressure exerted by an electromagnetic wave of Intensity I(W/m2) on a non-reflecting surface is (c = velocity of light)
(a) I c
(b) I c2
(c) I/c
(d) I/c2
Sol: $\large Intensity = \frac{Energy}{Area \times time} $
$\large I = \frac{F \times s}{A \times t} = \frac{F \times c}{A}$
$\large \frac{I}{c} = \frac{F}{A}$
$\large \frac{I}{c} = P $ ( Pressure = Force/Area )
Ans: (c)