# A circulating charged particle under a magnetic field

• eurekameh
In summary, the conversation explores the direction of rotation for electrons in a chamber immersed in a magnetic field. Despite initial assumptions that the electrons would rotate counter-clockwise based on the direction of the magnetic field, it is determined through the Right Hand Rule that the force on a positive charge is directed outwards, leading to a clockwise rotation. It is also noted that the velocity vector points in a direction that appears to be counter-clockwise.

#### eurekameh

http://imageshack.us/photo/my-images/543/unledyel.png/

This is a chamber, immersed in a magnetic field, containing circulating electrons shot into a gas. My question is: why is the direction of rotation for the electrons (as shown on the picture) clockwise and not counterclockwise? I am crossing v with B, which is directed outward of the page, and so, Fb is directed toward the center of the circle. However, with the direction of v and Fb known, I would think the electrons circulate counter-clockwise. Why is this not the case?

I applied the RHR and determined that the force on a positive charge is directed outwards from the balloon. Thus, the force reverses and points inwards for a negative charge.

Also, it doesn't look like their rotating about the centre axis clockwise at all. To me, it appears that the velocity vector points in the direction such that the particles go counter clockwise.

## 1. What is a circulating charged particle?

A circulating charged particle refers to a charged particle, such as an electron or a proton, that is moving in a circular motion due to the presence of a magnetic field.

## 2. What causes a charged particle to move in a circular path under a magnetic field?

A charged particle moves in a circular path under a magnetic field due to the Lorentz force, which is the force exerted on a charged particle when it is moving in a magnetic field.

## 3. How does the strength of the magnetic field affect the motion of a charged particle?

The strength of the magnetic field has a direct impact on the radius of the circular path that a charged particle will follow. A stronger magnetic field will result in a smaller radius, while a weaker magnetic field will result in a larger radius.

## 4. What is the relationship between the speed of the charged particle and the magnetic field?

The speed of the charged particle is also affected by the strength of the magnetic field. The particle will move at a higher speed with a stronger magnetic field, and at a lower speed with a weaker magnetic field.

## 5. How is the direction of the charged particle's motion determined by the magnetic field?

The direction of the charged particle's motion is determined by the right-hand rule, where the direction of the magnetic field, the direction of the particle's velocity, and the direction of the resulting force are all perpendicular to each other.