A charged particle is moving perpendicular to a magnetic field in a circle with a radius r. The magnitude of the magnetic field is increased. Compared to the initial radius of the circular path, the radius of the new path is which of the following

1_ larger

2_ smaller

3_equal in size

2_ smaller

The magnitude of the force on the particle is given by the magnetic component of the Lorentz force:

Where is the particle's charge, v its speed, B the magnetic field and is the angle between the particle motion and the magnetic field. According to the Newton's second law, we have:

Where is the centripetal force, replacing the values of thee forces and solving for r:

The radius is inversely proportional to the magnetic field. Therefore, if the magnetic field is increased, the radius of the new path is smaller.

b.a device that inputs heat into a cool object