Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to (1) $1 : 2$ (2) $4 : 1$ (3) $2 : 1$ (4) $1 : 4$
Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to\\
(1) $1 : 2$\\
(2) $4 : 1$\\
(3) $2 : 1$\\
(4) $1 : 4$