A capacitor is a system of two conductors separated by an insulator. The conductors have chargesQ and −Q,.
Do these conductors have the same magnitude of charge? and also can they different magnitude with opposite nature of charge
The conductors always have the same magnitude of charge and even if we try to induce charge on one plate rearrangement takes place which causes the magnitude to becomes equal again.
This is a basic idea of a capacitor.