Question

How many photons of red colored light having wavelength 8000 Å will have same energy as one photon of violet colored light of wavelength 4000 Å? 

(A) 2 

(B) 4 

(C) 6 

(D) 8

Answer 1

The correct option is (A) 2.

Explanation:

E₁ = (hc / λ₁) and E₂ = {(nhc) / λ₂}

Given energies are same 

Hence

(hc / λ₁) = {(nhc) / λ₂}

∴ n = (λ₂ / λ₁) = {(8000) / (4000)} = 2

∴ number of photons of red light = 2.