Light of wavelength ejects photoelectrons from a metal plate whose work function is

PHYSICS · Subjective · A Level · Physics · Particles and radiation · Particles and radiation

Problem

Light of wavelength

180\,\text{nm}

ejects photoelectrons from a metal plate whose work function is

2\,\text{eV}

. If a uniform magnetic field of

5\times10^{-5}\,\text{T}

is applied parallel to the plate, what is the radius of the path followed by electrons ejected normally from the plate with maximum energy?