A small cesium plate kept at a distance of 20cm from a large metal plate having a charge density of 1 nano coulomb/m2 .A monochromatic light of wavelength of 400 nm is incident on the cesium plates. Work function of cesium plate is 1.9 ev.Consider the fastest electron emitted parallel to the large metal plate.Find the displacement of this electron parallel to it's intial velocity before it strikes the large metal.