Which of the following parallel-plate capacitors hold the largest charge?

Question

A) A capacitor with area A and separation 2d connected to voltage 4V
B) A capacitor with area 2A and separation d connected to voltage 2V
C) A capacitor with area 2A and separation 2d connected to voltage V
D) A capacitor with area A and separation d connected to voltage V

Answer 1

C=q/U
C=εε₀A/d
q=CU= εε₀AU/d
A) q1= εε₀A4V/2d= 2 εε₀AV/d
B) q2 = εε₀2A2V/d= 4 εε₀AV/d max
C) q3 = εε₀2A V/2d= εε₀AV/d
D) q4 = εε₀A V/d= εε₀AV/d