Question

An electron having de-Broglie wavelength λ is incident on a target in a X-ray tube. Cut-off wavelength of emitted X-ray is :

(1) 0

(2) \(\cfrac{2m^2c^2\lambda^2}{h^2}\)

(3) \(\cfrac{2mc\lambda^2}h\)

(4) \(\cfrac{hc}{mc}\)

Answer 1

Correct option is (3) \(\cfrac{2mc\lambda^2}h\) 

\(\lambda=\cfrac{h}{m\text v}\)

kinetic energy,