Question

A photon of radiation of wavelength 4000 angstrom has an energy E.The wavelength of photon of radiation having energy 0.5E will be

Answer 1

Answer: 8000 angostrom

Explanation: here is the easiest way

We know that,

Energy of a photon,

E = hc/λ

here h and c are constants

Therefore E is inversely proportional by λ

Therefore, if anergy is halves to make it 0.5E,

Wavelength is doubled

Hence new wavelength, λ' = 2λ = 2 x 4000 angostrom

>> λ' = 8000 angostrom