# Direction of magnetic force

1. Dec 6, 2004

### agirlsrepublic

how do you find the direction of the magnetic force on a current loop..a loop that experiences a torque?
i know you use some kind of right hand rule but im confused

also..the direction of a charged particle in a magnetic field

Last edited: Dec 6, 2004
2. Dec 6, 2004

### Phymath

its the right hand rule, where ur fingers are in the direction of the current flow...im pretty sure

3. Dec 7, 2004

### James R

If you curl the fingers of your right hand in the direction the current flows around the loop, then your thumb points in the direction of the loop's magnetic dipole moment. The force on the loop will tend to align the dipole moment vector to be in the same direction as the external magnetic field the loop is sitting in.

The direction of the force on a charged particle in a magnetic field is:

$$\vec{F} = \vec{v} \times \vec{B}$$

where [itex]\vec{v}[\itex} is the velocity and [itex]\vec{B}[\itex] is the field.

Do you know how to apply the right hand rule to cross products such as this one?