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(C) The energy of a single photon is given by $E = h
u$,where $h = 6.63 	imes 10^{-34} \ J \cdot s$ and $
u = 6 	imes 10^{14} \ Hz$.$E = (6.63 	i

Vedclass · Accepted Answer

$10^4$

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(C) The energy of a single photon is given by $E = h
u$,where $h = 6.63 	imes 10^{-34} \ J \cdot s$ and $
u = 6 	imes 10^{14} \ Hz$.$E = (6.63 	imes 10^{-34}) 	imes (6 	imes 10^{14}) \approx 3.98 	imes 10^{-19} \ J$.The power $P$ entering the eye is given by $P = I 	imes A$,where $I = 10^{-10} \ W/m^2$ and $A = 0.4 \ cm^2 = 0.4 	imes 10^{-4} \ m^2 = 4 	imes 10^{-5} \ m^2$.$P = 10^{-10} 	imes 4 	imes 10^{-5} = 4 	imes 10^{-15} \ W$.The number of photons per second $n$ is given by $n = P / E$.$n = (4 	imes 10^{-15}) / (3.98 	imes 10^{-19}) \approx 1.005 	imes 10^4 \approx 10^4$ photons per second.

Calculate the number of photons entering the eye of a duck per second,corresponding to the minimum intensity of white light $(\sim 10^{-10} \ W/m^2)$. Take the area of the duck's eye as $0.4 \ cm^2$ and the average frequency of white light as $6 \times 10^{14} \ Hz$.

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