Q9 of 29 Page 70

Relativistic corrections become necessary when the expression for the kinetic energy becomes comparable with mc2, where m is the mass of the particle. At what de Broglie wavelength will relativistic corrections become important for an electron?

We know the de Broglie wavelength is given by,

where h is the Planck’s constant, m is the mass and v is the velocity



(a) When, λ =10nm




(b) When, λ =10–1nm




(c) When, λ =10–4nm




(d) When, λ =10–6nm




Hence, in cases (c) and (d) velocities are greater than the speed of light and hence relativistic corrections will become important for an electron.

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