Two parallel-plate capacitors 1 and 2 are identical except that capacitor 1 has charge \(+q\) on one plate and \(-q\) on the other, and capacitor 2 has charge \(+2 q\) on one plate and \(-2 q\) on the other. Compare the two capacitors based on their \((a)\) capacitance, \((b)\) potential difference between the plates, \((c)\) electric field magnitude between the plates, and \((d)\) energy stored.