A charged large metal sheet is placed perpendicular to a uniform external electric field. After introducing the sheet, the field magnitudes on its left and right sides are E₁ = 5 × 10⁵ V m⁻¹ and E₂ = 3 × 10⁵ V m⁻¹. The sheet experiences a net electric force of 0.08 N. Find the area of one face. Assume the external field remains constant. Use 1/(4πε₀) = 9 × 10⁹ N m² C⁻².

Question

G1 Physics · Accepted Answer

Step 1: Electrostatic pressure on a conductor face is p=ε₀E²/2. Net force is F=A(ε₀/2)(E₁²-E₂²). Step 2: A=2F/[ε₀(E₁²-E₂²)]. Using E₁=5×10⁵ and E₂=3×10⁵ V m⁻¹ gives A≈0.113 m². Step 3: 0.113 m² = 3.6π×10⁻² m². Final: A.