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

Since electron shows wave nature, it will show the phenomenon of interference.$\lambda =\frac{h}{mv}$

For electron:

When speed of electron increases, $\lambda$ will decrease. The distance between two consecutive fringes
$\beta =\frac{\lambda D}{d}$

As $\lambda$ decreases, $\beta$ also decreases.