Electricity and Magnetism - SS2 Physics Past Questions and Answers - page 4

When a charged particle moves in a uniform magnetic field, it experiences a magnetic force perpendicular to both its velocity and the magnetic field direction. The force acts as a centripetal force, causing the particle to move in a circular path. The radius of the circular path depends on the particle's velocity, charge, and the strength of the magnetic field. If the velocity is parallel or antiparallel to the magnetic field, there will be no magnetic force acting on the particle, and it will move in a straight line. If the velocity is at an angle to the magnetic field, the particle will follow a helical path.

The magnitude and direction of the magnetic force on a charged particle depend on several factors. Firstly, the magnitude of the force is proportional to the charge of the particle and the strength of the magnetic field. A greater charge or a stronger magnetic field will result in a larger force. Secondly, the direction of the force is perpendicular to both the velocity of the particle and the magnetic field direction, following the right-hand rule.

If the particle is positively charged, the force will be in one direction, while for a negatively charged particle, the force will be in the opposite direction. Lastly, the velocity of the particle also affects the force. The force is at a maximum when the velocity is perpendicular to the magnetic field and decreases as the angle between velocity and field increases.