NEETPhysicsDual Nature of Matter
An electron of mass m and a photon have the same de Broglie wavelength . The ratio of the kinetic energy of the electron to the energy of the photon is : (Take c as the speed of light and h as Planck's constant)
Options
- Ah 2mc
- B2mc h
- Ch mc
- D1
Correct answer
A. h 2mc
Step-by-step solution
Since the electron and the photon have the same de Broglie wavelength , they possess the same linear momentum p . The momentum is given by: p = h The kinetic energy of the electron E_e is related to its momentum by: E_e = p^2 2m = h^2 2m ^2 The energy of the photon E_ ph is related to its momentum by: E_ ph = pc = hc Taking the ratio of the kinetic energy of the electron to the energy of the photon: E_e E_ ph = h^2 2m ^2 hc = h 2mc Answer: h 2mc