There exists a uniform magnetic and electric field of  magnitude 1 T and 1 V /m, respectively, along positive y-axis. A charged particle of mass 1 kg and of charge 1 C is having velocity 1 m/s along x-axis and is at origin at t = 0. Then the co-ordinates of particle at time−π seconds will be

The particle will move in a non-uniform helical path with increasing pitch as shown below.Its time period will be:  T=2πmqB=2π  secondsChanging the view, the particle is seemed to move in a circular path in (X - Z) plane as shown belowAfter π-seconds the particle will be at point 'P' (after completing half circle), hence X coordinate of P will be 0.yπ=0π+12  Eqmπ2 = π22z=2r=2mv/qB=2mHence,  the  coordinate  0, π22,  2