The electric field at a point associated with a light wave is E = (100 V m^–1) sin [(3.0 × 10¹⁵ s^–1) t] sin [(6.0 × 10¹⁵ s^–1) t]. If this light falls on a metal surface having a work function of 2.0 eV, what will be the maximum kinetic energy of the photoelectrons?

Given, work function Ф =2 eV

Solving the above equation using formula,

∴

From the above equation there are two values of W

∴ for maximum kinetic energy W should be maximum

∵ =

And also from Einstein’s photoelectric equation,

⇒

∴ Kinetic energy will be maximum when f (frequency) is

Maximum and f will be maximum when W is maximum.

⇒

⇒

K= 3.93 eV.