Charge of uniform density (20 nC/m2) is distributed over a cylindrical surface (radius = 1 cm), and a second coaxial surface (radius = 3 cm) carries a uniform charge density of -12 nC/m2.
1. Determine the magnitude of the electric field at a point 2 cm from the symmetry axis of the two surfaces.
2. Determine the magnitude of the electric field at a point 4 cm from the symmetry axis of the two surfaces.
The answers are 1.1 kN/C and 0.45 kN/C respectively.
Please show the work.