# Magnetic force

- If a charge is moving through a magnetic field, the force on the charge is given by:

F = qvB

- q = charge (C)
- v = velocity of the charge moving through the field (m/s)
- B = the perpendicular flux density through which the charge moves (T)

- The direction of the applied force is given by the right hand rule.
- If the charge is negative, the force will be in the opposite direction.

### Right Hand Rule

- Thumb points in the direction of the force (positive)
- Index point in the direction of velocity
- Middle finger points in the direction of the magnetic field

### Force on a current-carrying conductor

If a current carrying wire produces its own magnetic field, and it were placed in an external magnetic field,

- The magnetic fields will interact
- In some instances, the magnetic field will apply a force to the wire.

Using the formula,

F = ILB

- I = current (A)
- L = length (m)
- B = magnetic flux density perpendicular to the current (T)

Direction is given by the right hand rule.

### Angled magnetic flux

If the magnetic flux is not at right angles to the current carrying conductor, the perpendicular flux is equal to Bsinθ, where theta = angle that the flux makes to the conductor.

Hence,

F = ILBsinθ