Question
The energy of a photon of wavelength $$\lambda $$ is
A.
$$hc\lambda $$
B.
$$\frac{{hc}}{\lambda }$$
C.
$$\frac{\lambda }{{hc}}$$
D.
$$\frac{{\lambda h}}{c}$$
Answer :
$$\frac{{hc}}{\lambda }$$
Solution :
According to Planck’s quantum theory, a source of radiation emits energy in the form of photons, which travel in straight line. The energy of a photon is given by
$$E = h\nu = \frac{{hc}}{\lambda }$$
where, $$h =$$ Planck's constant $$ = 6.62 \times {10^{ - 34}}J{\text{ - }}s$$
$${\nu _1}$$ and $$\lambda =$$ frequency and wavelength of photon, respectively
$${\text{and}}\,c = {\text{speed}}\,{\text{of}}\,{\text{light}} = 3 \times {10^8}m/s$$