Show that the electric field due to a point charge is conservative?

Obtain expression for electric field due to a point charge

Graphically, represent the variation of electric field due to a point charge Q with magnitude of charge Q

Show that the electric field intensity at a point in an electric field is equal to the negative of the potential gradient of the field at that point. E = -(dV)/(dr)

Graphically, represent the variation of electric field due to a point charge Q with 1//r^2 where r is the distance of the obervation point from the charge.

Derive expression for the electric field due to a uniformly charged spherical shell at a point outside the shell.

Derive expression for the electric field due to a uniformly charged spherical shell at a point inside

Draw the electric field lines due to a uniformly charged thin spherical shell when charge on the shell is negative?

Draw the electric field lines due to a uniformly charged thin spherical shell when charge on the shell is positive?