CAPACITANCE AND CAPACITORS Flashcards
a passive device for storing electric charges
Capacitors
two parallel conducting plates separated from each other by a thin sheet of insulating material or dielectric.
simplest type of capacitor
Classification of Capacitors
Parallel- plate capacitors.
Cylindrical capacitors
Spherical Capacitors
This type of capacitor has two parallel charging plates are
separated by a dielectric that contains charges. The
capacitance is directly proportional to the area of the plates as well as to the distance between these plates
Parallel- plate capacitors
Have different construction with inner and outer __________ structures. The capacitance of a ____________________ varies
directly with its length. Longer capacitor provides higher
capacitance, whereas a shorter provides a lower value.
cylindrical, cylindrical capacitor
have an internal __________ structure and it is one of the charged bodies of the capacitor. The other charged body is the outer __________ structure that covers the internal sphere. The capacitance of this capacitor varies directly with its overall radius. Increasing the radius of this type of capacitor will enlarge the _____________ surface.
Spherical Capacitors
is the ability of a capacitor to
store charges
Capacitance
mathematically defined as the ratio of the amount of charge q in one plate to the potential difference V between the plates.
capacitance C of a
capacitor
Formula for Capacitance
C=q/V
Unit for Capacitance
Coulomb per Volt (C/V)
Farad (F)
The capacitance of a parallel plate capacitor is affected by the following factors:
- The area of plates.
- The distance between the plates.
- The insulating material or dielectric between them. (material’s permittivity)
The bigger the area of the
plates, the greater the capacitance.
area of plates
The closer the plates to each other, the greater the capacitance.
distance between the plates
The capacitance is determined in terms of
the material’s permittivity constant є – the higher the є, the greater the capacitance.
insulating material or dielectric between
them
The dependence of the capacitance of a
parallel plate capacitor on the factors
cited is mathematically expressed as:
𝑪 = 𝑨 𝜺/𝒅 ; 𝜺=C^2/Nm^2
