Question

The number of photons of light having wave number $x$ in 1 J of energy source is (Plancks constant = h, velocity of light = c):

• A. $hcx$
• B. $\frac{hc}{x}$
• C. $\frac{x}{hc}$
• D. $\frac{1}{hcx}$

Answer 1

The correct option is D $\frac{1}{hcx}$

The energy of one photon $=hc\overline{\nu }=hcx$

The number of photons $=\frac{\text{Total energy}}{\text{Energy of one photon}}=\frac{1}{hcx}$
Option (D) is correct.