Question

Light oscillates in both time and space. Considering light absorption or emission, when can the spatial oscillation be ignored?

Question 5 options:

a)	When the atom is much larger than the light wavelength

b)	When the wavelength is much larger than the atom

c)	When the electric field is much larger than the coulomb interaction

d)	When the magnetic field is much larger than the coulomb interaction

e)	When the magnetic field is much larger than the spin-orbit coupling

Answer 1

ANS - B, C, E

When the wavelength of light is much larger than the atom then for the atom, light acts like a wave and not photon beam.

Also, diffraction will not happen in this situation.

During atomic transitions, absorption and emission are only time-dependent and not space independent

When the Magnetic field is larger than Spin-orbit coupling, Strong Zeeman effect, we consider Spin dependence too.

While when the Electric field is larger than the interaction between dipole moments of the electron and Electric field