AP EAMCET Engineering 2018 Apr 24 Shift 1 Paper

The energy is calculated as:
E=h

c

λ

=6.6×10−34Js×

3×108m∕s

450×10−9m

=4.4×10−19J
The energy in eV is derived as:
1eV=1.602×10−19
Energy=

4.4×10−19

1.602×10−19

=2.74eV
The metals which are having less value of work function than the energy calculated, they can undergo photoelectric effect.
Therefore, metals are K, Na and Li.