Physics - Magnetism Question with Solution | TestHub

The shaded area in the figure is the side view of a disk shaped magnetic field region of radius R and thickness d. A parallel electron beam being accelerated by a voltage V is normally incident onto the region. If the spatial distribution of the magnetic field in the region such that the beam is focused to a point along the disk central axis at a distance $\mathrm{L}(>\mathrm{R})$ from the disk is $\mathrm{B}=\frac{\mathrm{y}\eta }{{\mathrm{d}}^{\alpha }\mathrm{L}\beta }\sqrt{\frac{\lambda \mathrm{mV}}{\mathrm{e}}}$, find the value of $\frac{5\alpha }{\lambda +\beta +\eta }$. Given m and e are the electron's mass and charge and y is the distance of incident electron from axis of disc.