Question

The number of photons that pass
through a unit area in a unit time is
called

amplitude of light
frequency of light
intensity of light
wavelength of light
​

Answer 1

Explanation:

Given :   λ=900 nm=900×10−9 m

Energy of one photon   E=λhc

⟹ E=400×10−96.6×10−34×3×108=4.95×10−19 J

Total energy of light falling per second per unit area   Et=100 J

Number of photons   N=EEt=4.95×10−19100=2×1020  photons per second

Answer 2

Answer:

intensity of light is the answer