Question

A beam of electrons is used in Young's double-slit experiment. If the speed of electrons is increased then the fringe width will ______.

Options

• increase

• decrease

• remains same

• fringes will not be seen

Answer 1

A beam of electrons is used in Young's double-slit experiment. If the speed of electrons is increased then the fringe width will decrease.

Explanation:

For electron `lambda = h/p = h/(mv)`

Fringe width `beta = (lambda "D")/"d" = (h"D")/(mvd)`

`=> beta prop 1/v`

Hence speed increased then fringe width will decrease.