A particle of mass m and positive charge q travels with a uniform velocity v and enters a region of magnetic field B , as shown in the figure. How much time does the particle spend inside the magnetic field?

Step-by-step solution

When a particle of mass m and positive charge q enters a uniform magnetic field B perpendicular to its velocity, it moves in a circular path with an angular speed = qB m . The magnetic field is directed into the page. Applying the right-hand rule for the magnetic force F = q( v B ) , the force on the positive charge at the point of entry is directed upwards and to the right. This indicates that the center of the circular path lies outside the magnetic field region. The particle enters the field at an angle with the