A plane electromagnetic wave of intensity 10 Wm−2 strikes a small mirror of area 20 cm2 , held perpendicular to the approaching wave. The radiation force on the mirror will be
Answer & explanation
Correct answer: option 3
Radiation force=momentum transferred per sec by electromagnetic wave to the mirror
$=\frac{2S_{av}A}{c}=\frac{2×(10)×(20×10^{-4})}{(3×10^8)}$
$=1.33 × 10^{-10} N$