The photo electric threshold wave length of silver is $3250 \times 10^{-10}\;m$ . The velocity of the electrons ejected from a silver surface by ultraviolet light of wavelength $2536 \times 10^{-10}\;m$ is : (Given $h=4.14 \times 10^{-10} \;eVs$ and $c= 3 \times 10^{8} \;ms^{-1})$