A plane electromagnetic wave of wave intensity 6 W/m² strikes a small mirror of area 40 cm², held perpendicular to the approaching wave. The wavelength of the wave will be:

1.5 cm

Wavelength of electromagnetic wave

$\lambda=\frac{c}{v}=\frac{3 \times 10^8}{2 \times 10^{10}}=1.5 \times 10^{-2}$ = 1.5 cm

Hence correct answer will be (C)