Question

A beam of electron is used in a YDSE experiment. The slit width is 'd'. When the velocity of electron is increased, then

• A. no interference is observed
• B. fringe width increases
• C. fringe width decreases
• D. fringe width remains same

Answer 1

The correct option is C fringe width decreases

For electron, $\lambda =\frac{h}{mv}$

$\beta =\lambda \frac{D}{d}=\frac{hD}{mvd}$

So higher the velocity, less the fringe width

Answer. C) fringe width decreases.