Charge of uniform surface density (0.20 nC/m2) is distributed over the entire xy plane.Determine the magnitude of the electric field at any point having z = 2.0 m.
A)17 N/C
B)11 N/C
C)23 N/C
D)28 N/C
E)40 N/C

Question

Quizplus · Accepted Answer

The electric field at any point above the xy plane due to a uniformly charged infinite sheet is given by:
E = σ/2ε0
where σ is the surface charge density and ε0 is the electric constant.
Substituting the given values,
E = (0.20 nC/m2) / (2ε0)
E = (0.20 × 10^-9 C/m2) / (2 × 8.85 × 10^-12 C^2/N m^2)
E = 11.30 N/C
Since the direction of the electric field due to an infinite sheet of charge is perpendicular to the sheet, the magnitude of the electric field at any point with z = 2.0 m is also 11.30 N/C. Rounded to the nearest whole number, the answer is 11 N/C, which corresponds to choice B.

Charge of Uniform Surface Density (0