The maximum velocity of an electron emitted by light of wavelength ′λ′ incident on the surface of a metal of work-function ϕ is
When a point light source, of power W emitting light of wavelength λ is kept at a distance 'a' from a photosensitive surface of work function ϕ and area S, we will have
The path difference between the two waves y1=a1sin(ωt−2πxλ)and y2=a2 cos(ωt−2πxλ+ϕ) is