A charged particle of specific charge (charge/mass) o is released from origin at time t= 0 with velocity v→=v0(i^+j^)in uniform magnetic field B→=B0i^. Coordinates of the particle at time t=π/B0α are

α=qmpath of the particle will be a helix of time period,T=2πmB0q=2πB0α  The given time t=πB0α=T2∴   Coordinates of particle at time t=T/2  would be vxT/2,0,-2r  Here, r=mv0B0q=v0B0α ∴   The coordinates are v0πB0α,0,-2v0B0α.