(A
Level)
All moving charges
create a magnetic field. If the charge is moving at right angles to
the flux lines then the field it creates interacts strongly with the
fixed magnetic field and the charge experiences a maximum motor effect
force.
When
a moving charge is placed in a magnetic field, it may experience
a force.
The maximum force
it experiences is when it is travelling at right angles to the flux
lines. When it is parallel to them it is zero. The relationship can
be determined by the sine of the angle the velocity of the particle
makes with the flux lines. (When the angle is zero (parallel) then
force is zero as sin 0o = 0 and it is maximum when angle
is 90o sin 90o = 1)
The size of the force can be increased
by:
. increasing the strength of the
magnetic field it experiences;
. increasing the size of the charge
on the particle.
. decreasing the mass of the particle.
You
can use FLHR to check
that the particles have been moved in the correct direction.
Remember
that the second finger represents the current - this is the finger
that has to point in the direction of the velocity vector of positive
charge movement. If you have a negative charge it has to point in
the opposite direction to the velocity vector of that particle!
Note
that the bigger mass of the alpha particle outweighs the bigger charge
factor. This makes it change direction less than the beta particle...
the force has less effect. The gamma is unaffected as it has no charge!