The distance between laser source and receiver does not affect the energy of each photon incident, hence does not affect the energy of emitted photoelectrons.
But the reduction in distance will increase the intensity of incident light and hence number of photons. This will increase the photoelectric current.
where, wavelength of incident radiation is λ = 3300 Å
So, energy of incident radiation is
E =

hc

λ

=

6.3×10−34×3×108

3300×10−10×1.6×10−19

= 3.75 eV
Now, work function of Mo : 4.17 eV, Ni : 5.15 eV is more than energy of incident photon, hence these two metals will not give photoelectric emission.