A Cs plate is irradiated with a light of wavelength `lamda=(hc)/(phi)`,`phi` being the work function of the plate, h Plank's constant, and c the velocity of light in vacuum. Assume all the photoelectron are moving perpendicular to the plate toward a YDSE setup when accelerated through a potential difference V. Take charge on a proton `=e` and moss of an electron `=m`. Read the paragraph carefully and answer the following question:
Q. If the wavelength of light used in photoemission is less that `lamda`, then the fringe width will

Options

A. increase
B. decrease
C. remain same
D. cannot be dicided

Answer

B

Explanation

As v increases, `lamda` decreases.