Question

IP
1. A positive charge particle of charge q and
mass m enters into a uniform magnetic field
with velocity v as shown in figure. There is
no magnetic field to the left of PO.
Find (a) time spent, (b) distance travelled in
the magnetic field, (c) impulse of magnetic
force.
VO ;
Q​

Answer 1

a) As the magnetic field is uniform, the charge comes out symmetrically. Hence, α=β

b) v=v

0

since the speed does not change during motion in a plane perpendicular to the magnetic field

c)r=

qB

mv

0

Length of arc PQ:2rsinα=

qB

2mv

0

sinα

d) T=

qB

2πm

Time spent inside magnetic field is

T×

2π

(2π−2α)

=

qB

2πm

×

2π

(2π−2α)

=

qB

2m

(π−α)

solution