NEETPhysicsDual Nature of Matter
A photon and an electron (mass m ) are found to have the exact same de Broglie wavelength . If c is the speed of light and h is Planck's constant, the ratio of the energy of the photon to the kinetic energy of the electron is:
Options
- A2mc h
- Bh 2mc
- C2m hc
- Dc 2m
Correct answer
A. 2mc h
Step-by-step solution
The energy of a photon in terms of its wavelength is given by: E_ photon = hc For an electron of mass m , the de Broglie wavelength is = h p , so its momentum is p = h . The kinetic energy of the electron is: E_ electron = p^2 2m = h^2 2m ^2 Taking the ratio of the energy of the photon to the kinetic energy of the electron: E_ photon E_ electron = hc h^2 2m ^2 E_ photon E_ electron = hc 2m ^2 h^2 = 2mc h Answer: 2mc h