The problem requires us to determine the correct graph for the electric potential \(V\) as a function of the distance \(r\) from the center of a uniformly charged spherical shell with radius \(R\).
A uniformly charged spherical shell has the following properties related to electric potential:
The potential graph should show a constant value from the center to the surface \((r = R)\), and then start decreasing as \(r\) increases beyond the surface.
This graph shows that the potential is constant within the shell \((r < R)\) and decreases for \(r \geq R\), which matches the theoretical behavior of a uniformly charged spherical shell.
The correct graph for the electric potential \(V\) as a function of distance \(r\) from the center of the charged spherical shell is option 4.
Two charges, \( q_1 = +3 \, \mu C \) and \( q_2 = -4 \, \mu C \), are placed 20 cm apart. Calculate the force between the charges.