Question
Question: A charged particle q enters a region of uniform magnetic field B (out of the page) and is deflected ...
A charged particle q enters a region of uniform magnetic field B (out of the page) and is deflected d after traveling a horizontal distance a. The magnitude of the momentum of the particle is–

A
2qB
B
2qB0
C
Zero
D
Not possible to be determined as it keeps changing
Answer
2qB
Explanation
Solution
Q AB == h(say)
In DOAD

Fig. cos q = … (i)
Now, In DACB sin (2π−θ)= … (ii) From (i) and (ii)
=
\ h2 = 2Rd R =
=
Now, = qvB mv = qBR
Momentum = qB × (2da2+d2)