Physics

Problem

A beam of electromagnetic radiation of intensity

6.4 \times 10^{-5} \text{ W/cm}^2

is comprised of wavelength,

\lambda = 310 \text{ nm}

. It falls normally on a metal (work function

\phi = 2 \text{ eV}

) of surface area of

1 \text{ cm}^2

. If one in

10^3

photons ejects an electron, total number of electrons ejected in

1 \text{ s}

10^x

. (

hc = 1240 \text{ eV nm}

1 \text{ eV} = 1.6 \times 10^{-19} \text{ J}

), then

x

is ________.