The Cross Section of a Long Coaxial Cable Is Shown

Multiple Choice

The cross section of a long coaxial cable is shown in the figure, with radii as given. The linear charge density on the inner conductor is -30 nC/m and the linear charge density on the outer conductor is -70 nC/m. The inner and outer cylindrical surfaces are respectively denoted by A, B, C, and D, as shown. (ε0 = 8.85 × 10^-12 C²/N ∙ m²) The radial component of the electric field at a point that 34 mm from the axis is closest to

A) -16,000 N/C.
B) +16,000 N/C.
C) -37,000 N/C.
D) +37,000 N/C.
E) zero