You indicated that the direction of the magnetic force at point A is direction 8. 

Magnetic force is related to the magnetic field through the relationship:

where   = the magnetic force,

 = the magnetic field,

 = the velocity of the charged object,

            q = the charge of the object that is moving through the magnetic field.

The ‘’ in the equation is the ‘cross product’ between the velocity and magnetic field.  If you have not encountered cross products in your math classes, then this relationship can be written as:

magnitude of F_mag^:

direction of F_mag:         obtained from the right hand magnetic force rule.

where θ = the angle between  and .

As indicated, the direction of the magnetic force is obtained from the ‘right hand’ magnetic force rule.  Unfortunately, there are several variations of this rule.  Two of these variations are illustrated here, but feel free to use whichever variation you prefer.  Click the radio button to alternate between these two variations. 

Variations:

· Right Hand Rule #1

As illustrated in the diagram above, extend your fingers so that your right hand is flat, then point your fingers in the direction of the velocity of the charged object.  While your fingers continue to point in the direction of the velocity, rotate your palm so that when you bend your fingers, they point in the direction of the magnetic field.  Your thumb then points in the direction of the magnetic force. 

· Right Hand Rule #2

As illustrated in the diagram above, hold your first finger, middle finger and thumb of your right hand so that they are all perpendicular to each other (like the x, y and z axes).  With your fingers in this awkward position, orient your hand so that your first finger points in the direction of the velocity and your middle finger points in the direction of the magnetic field.  Your thumb then points in the direction of the magnetic force.