PhysicsMedium145×since 2002Q6604A parallel beam of light of wavelength 900 nm900 \mathrm{~nm}900 nm and intensity 100 Wm−2100 \,\mathrm{Wm}^{-2}100Wm−2 is incident on a surface perpendicular to the beam. The number of photons crossing 1 cm21 \mathrm{~cm}^{2}1 cm2 area perpendicular to the beam in one second is :A3×10163 \times 10^{16}3×1016B4.5×10164.5 \times 10^{16}4.5×1016C4.5×10174.5 \times 10^{17}4.5×1017D4.5×10204.5 \times 10^{20}4.5×1020Check answerSkip