Electronic – Does the physical size of through-hole ceramic capacitors relate to voltage rating


I am sorting through some ceramic capacitors and reorganizing them. I came across a number of capacitors with "82" on them (at left), which I assume is 82pF, but they are physically larger than even my 0.1μF capacitors (at right).

Ceramic Caps

Does the large size of these capacitors relate to their voltage rating (or something else), or did I misinterpret the capacitance value?

Best Answer

For a big capacitor the distance should be low and area should be high because capacitance is directly proportional to area of the plates and inversely proportional to the distance between the plates. But if the distance is too low, the dielectric will get punctured with voltage. So there must be a proper distance between the plates according to voltage; and for that distance, the area should be high as to get the required capacitance.

So in any capacitor, the size depends on voltage and its capacitance value because voltage rating is proportional to distance between plates and capacitance is proportional to area of the plates.