Question

Stopping potential for e- for wavelength 491 nm is 0.410 V incidence wavelength is changed to new value then stopping potential is 1.02 V. New wavelength is

Options: (a) 234.62 nm (b)582.65 nm (c) 104.32 nm (d) 645.83 nm

Answer 1

Answer is  (d) 645.83 nm

Answer 2

It D Bro 1240 / 1.92 =645.83