Parallel Plates: Two Flat 4

Multiple Choice

Parallel plates: Two flat 4.0 cm × 4.0 cm electrodes carrying equal but opposite charges are spaced 2.0 mm apart with their midpoints opposite each other. Between the electrodes but not near their edges, the electric field strength is 2.5 × 10⁶ N/C. What is the magnitude of the charge on each electrode? (ε₀ = 8.85 × 10^-12 C²/N ∙ m²)

A) 35 nC
B) 18 nC
C) 16 nC
D) 30 nC