The energy flux of sunlight reaching the surface of the earth is 1.388 x 10³ W/m². How many photons (nearly) per square metre are incident on the earth per second? Assume that the photons in the sunlight have an average wavelength of 550 nm.

Solution

Energy flux of sunlight = Total energy per square metre per second = 1.388 x 10³ Wm^–2Energy of each photon is given by,

$E = \frac{hc}{λ}$
Therefore,
$Power of each photon, P = nE = \frac{6.63 \times 10^{- 34} \times 3 \times 10^{8}}{550 \times 10^{- 9}} J = 3.62 \times 10^{- 19} J$
Number of photons incident on earth's surface per square metre per second is,

$= \frac{Total energy per square metre per second}{Energy of one photon}$

$= \frac{1.388 \times 10^{3}}{3.62 \times 10^{- 19}} = 3.8 \times 10^{21} .$

For Daily Free Study Material Join wiredfaculty

Wave Optics

The energy flux of sunlight reaching the surface of the earth is 1.388 x 10³ W/m². How many photons (nearly) per square metre are incident on the earth per second? Assume that the photons in the sunlight have an average wavelength of 550 nm.

Some More Questions From Wave Optics Chapter

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Loaction

For Daily Free Study Material Join wiredfaculty

Wave Optics

The energy flux of sunlight reaching the surface of the earth is 1.388 x 103 W/m2. How many photons (nearly) per square metre are incident on the earth per second? Assume that the photons in the sunlight have an average wavelength of 550 nm.

Some More Questions From Wave Optics Chapter

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

The energy flux of sunlight reaching the surface of the earth is 1.388 x 10³ W/m². How many photons (nearly) per square metre are incident on the earth per second? Assume that the photons in the sunlight have an average wavelength of 550 nm.