An alpha particle is projected with an initial velocity perpendicular to a region where a uniform electric field and a uniform magnetic field are acting parallel to each other. What will be the shape of the path traced by the alpha particle?

Step-by-step solution

Let the uniform electric field E and magnetic field B be along the y-axis, and the initial velocity v of the alpha particle be along the x-axis. The component of velocity perpendicular to the magnetic field causes the alpha particle to experience a magnetic force F _m = q( v B ) , which provides the centripetal force for circular motion in the x-z plane. Simultaneously, the electric field exerts a constant force F _e = q E on the positively charged alpha particle along the y-axis. This causes a constant acceleratio