Answer:
Explanation:
Force on a moving charge is given by the following relation
F = q ( v x B )
for proton
q = e , v = vi , B = Bk
F = e ( vi x Bk )
= Bev - j
= - Bevj
The direction of force is along negative of y axis or -y - axis.
for electron
q = - e , v = vi , B = Bk
F = - e ( vi x Bk )
= - Bev - j
= Bevj
The direction of force is along positive of y axis or + y - axis.
To solve this problem we will apply the concepts related to wavelength, as well as Rayleigh's Criterion or Optical resolution, the optical limit due to diffraction can be calculated empirically from the following relationship,

Here,
= Wavelength
d= Diameter of aperture
= Angular resolution or diffraction angle
Our values are given as,

The frequency of the sound is 
The speed of the sound is 
The wavelength of the sound is

Here,
v = Velocity of the wave
f = Frequency
Replacing,


The diffraction condition is then,

Replacing,

d = 0.24 m
Therefore the diameter should be 0.24m