Magnetic and electric fields can cause a charged particle to form interesting trajectories. In
general, each trajectory is discussed separately in university physics textbooks for undergraduate
students. In this work, a solution of a charged particle moving in a uniform electric field at right
angles to a uniform magnetic field (uniform crossed electric and magnetic fields) is reported; it is
limited to particle motion in a plane. Specific solutions and their trajectories are obtained only
by varying the initial particle velocity. The result shows five basic trajectory patterns, i.e.,
straight line, sinusoid-like, cycloid, cycloid-like with oscillation, and circle-like. The region of
each trajectory is also mapped in the initial velocity space of the particle. This paper is intended
for undergraduate students and describes further the trajectories of a charged particle through the
regions of electric and magnetic fields influenced by initial condition of the particle, where
elec…