A beam of electron is used `YDSE` experiment . The slit width is d when the velocity of electron is increased ,then

Options

A. No interference is observed
B. Fringe width increases
C. Fringe width decreases
D. Fringe width remains same

Answer

B

Explanation

In this case , instead of monochromatic light a beam of electrons is used. Hence we have to consider their de broglie wavelength . `lamda = (h)/(mv)`
In Young's double slit experiment , fringe width `X = (lamdaD)/(d)`
When the velocity of the electrons is decreased , its de broglie wavelength is increased.
`because X prop lamda`, the fringe width will increase.