let us discus the direction of magnetic force
on a moving charge when it enters into magnetic
field. here we can see this is our magnetic
induction. which exist in, the direction into
the plane of the sheet that is inward direction.
and from one of its boundary. a positive charge
q enters into it with a velocity vector v.
we already discussed that, the magnetic force
acting on the charge is given by q v cross
b. so here we can see the direction of magnetic
force. will be given by the cross product
of velocity vector and magnetic field vector.
here velocity vector is in rightward direction
and magnetic field is in inward direction.
so by using righthand thumb rule we can find
out the direction of this force vector. here
if i rotate my righthand fingers from v vector
to b vector you can see my thumb is pointing
in upward direction. so as soon as the charge
enters into the magnetic field it experiences
the magnetic force vector in the direction.
perpendicular to both v vector and b vector
and the direction is given by righthand thumb
rule, that is cross product of v and b vector.
so due to this direction of charge particle,
motion will bend in upward direction due to
the force. and important thing is the direction
of f-m vector which we have calculated by
righthand thumb rule. but one more thing i
would like to write here that is direction
of. f-m vector can be given by. righthand
thumb rule. or. another rule which we frequently
use that is righthand palm rule. which i am
going to explain now. this righthand palm
rule is another rule which we use here that
will be more comfortable to analyze the direction
of magnetic force. and about righthand palm
rule, we can directly state it is explain
in a way that. if you stretch righthand. here
you just see the realistic situation also.
here. if righthand is stretched. with. fingers
pointing in the direction of b vector here
you can see. this is the righthand of someone.
and here we are pointing the fingers in the
direction of magnetic induction that is pointing
inward. and if we keep our thumb along the
direction of velocity vector of positive charge.
which is here towards right so here you can
see if we rotate this hand in such a way.
that magnetic induction is. pointed by the
fingers and thumb is along the direction of
v vector. then we can say. the palm face.
will give us the direction of magnetic force
vector here you can see that magnetic force
is acting in upward direction, so this is
the way how righthand palm rule is applied
you can also visualize that by using your
own righthand palm because. in many different
situation you need to use this rule.
