Light of frequency $2 ν_{0}$ ( $ν_{0}$ = threshold frequency) ejects photoelectrons of maximum kinetic energy $K_{1}$ . When the frequency is raised to $4 ν_{0}$ on the same metal, the maximum kinetic energy becomes $K_{2}$ . The ratio $K_{2} / K_{1}$ is

Answer: A

K = h nu - h nu0. K1 = 2h nu0 - h nu0 = h nu0, and K2 = 4h nu0 - h nu0 = 3h nu0. So K2/K1 = 3, not the frequency ratio 2.