Answer:
The magnitude of the magnetic field 'B' is 0.16 Tesla.
Step-by-step explanation:
The magnitude of the magnetic field 'B' can be determined by;
B =

where: m is the mass of proton, V is its speed , q is the charge of proton and R is the distance between the plates.
Given that: speed 'V' of the proton = 3.5 ×
, distance 'R' between the plates = 0.23m, the charge 'q' on proton = 1.9 ×
C and mass of proton = 1.67 ×
Kg.
Thus,
B = (1.67 ×
× 3.5 ×
) ÷ (1.6 ×
× 0.23)
=

= 0.15883
B = 0.16 Tesla
The magnitude of the magnetic field 'B' is 0.16 Tesla.