When photons of energy 4.25 eV strike the surface of a metal 'A', the ejected photoelectrons have ma — Atomic Structure Chemistry Question

Question

When photons of energy 4.25 eV strike the surface of a metal 'A', the ejected photoelectrons have maximum kinetic energy, $T_A$ (in eV) and de-Broglie wavelength, $\lambda_A$. The maximum kinetic energy of photoelectrons liberated from another metal 'B' by photons of energy 4.20 eV is $T_B$ ($= T_A - 1.50$ eV). If the de-Broglie wave length of these photoelectrons is $\lambda_B$ ($= 2\lambda_A$), then