capacitance

• a parallel plate capacitor is made up of two metal plates with an insulator between them, the distance between the plates is called the gap
• capacitors are used as energy stores because they can store electrical potential energy when charged
• The time constant of a discharging capacitor is the time taken for the charge to decrease to e$^-$$^1$of its original value
• The capacitance of two plates is directly proportional to the area of the two plates and inversely proportional to the distance between them