In Figure below, an electron accelerated from rest throughpotential difference V1=1.31 kV enters the gapbetween two parallel plates having separation d = 21.0 mmand potential difference V2= 111 V. The lowerplate is at the lower potential. Neglect fringing and assume thatthe electron's velocity vector is perpendicular to the electricfield vector between the plates. In unit-vector notation, what uniform magnetic field allows the electron to travel in a straightline in the gap?