Which of the following figures represent the variation of particle momentum and the associated de-Broglie wavelength?

A certain metallic surface is illuminated with monochromatic light of wavelength, $$\lambda .$$ The stopping potential for photo-electric current for this light is 3V₀. If the same surface is illuminated with light of wavelength 2 $$\lambda $$, the stopping potential is V₀. The threshold wavelength for this surface for photo-electric effect is

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de Broglie wavelength of the particle is

When the energy of the incident radiation is increased nby 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is