Texts: Two long, charged, thin-walled, concentric cylindrical shells have radii of r₁ = 3.0 cm and r₀ = 6.0 cm. The charge per unit length is -7.0 x 10⁻⁶ C/m on the inner shell and 5.0 x 10⁻⁶ C/m on the outer shell. What is the magnitude of the electric field at a radius r = 5.5 cm?
-2.3 × 10⁶ N/C.
2.3 × 10⁶ N/C.
-3.1 x 10⁶ N/C.
O 3.1 x 10⁶ N/C.