The energy flux of sunlight reaching the surface of the earth is $1.388 \times 10^{3} \; W/m^{2}$. 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 $550 \; nm$.

  • A
    $9 \times 10^{22} \; \text{photons}/m^{2} \cdot s$
  • B
    $6 \times 10^{22} \; \text{photons}/m^{2} \cdot s$
  • C
    $8 \times 10^{20} \; \text{photons}/m^{2} \cdot s$
  • D
    $4 \times 10^{21} \; \text{photons}/m^{2} \cdot s$

Explore More

Similar Questions

$A$ $2\,mW$ laser operates at a wavelength of $500\,nm.$ The number of photons that will be emitted per second is [Given Planck's constant $h = 6.6 \times 10^{-34}\,Js,$ speed of light $c = 3.0 \times 10^8\,m/s$]

$A$ gamma ray photon creates an electron-positron pair. If the rest mass energy of an electron is $0.5\, MeV$ and the total kinetic energy $(K.E.)$ of the electron-positron pair is $0.78\, MeV$,then the energy of the gamma ray photon must be.......$MeV$.

The approximate wavelength of a photon of energy $2.48 \,eV$ is ............ $\mathring A$.

$A$ transmitter of $100 \ W$ power emits electromagnetic waves of wavelength $540 \ nm$. How many photons are emitted per second? (Given: $h = 6 \times 10^{-34} \ J \cdot s$,$c = 3 \times 10^8 \ m/s$)

There are materials which absorb photons of shorter wavelength and emit photons of longer wavelength. Can there be stable substances which absorb photons of larger wavelength and emit light of shorter wavelength?

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo