Ultraviolet radiation of falls on an aluminium surface with work function

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

Ultraviolet radiation of

6.2\,\mathrm{eV}

falls on an aluminium surface with work function

4.2\,\mathrm{eV}

. The kinetic energy in joules of the fastest electrons emitted is (1)

3.2\times10^{-21}

(2)

3.2\times10^{-19}

(3)

3.2\times10^{-17}

(4)

3.2\times10^{-15}