Parallel-Plate capacitors

Capacitor

A device used to store electrical charge and electrical energy.

This device generally consists of two electrical conductors separated by distance.

Electrodes, capacitor plates

Two different names in which the “electrical conductors” of this device is addressed

Vacuum capacitor

When the space between the capacitor simply is a vacuum.

Dielectric

The insulating material used to fill the space between the capacitors

Capacitance

Property of the capacitor that determines the amount of storage in a capacitor.

In other words, the largest amount of charge per volt that can be stored on the device.

10^-12 F to 10^-3 F

Typical capacitance value range

Radio reception

The process by which a radio receiver captures radio waves transmitted through the air and converts them into usable audio or data signals for the listeners.

Static

Refers to the unwanted noise, interference, and random electrical signals that disrupt the clarity of the received radio signal.

Filtering the static from radio reception and energy storage in the heart defibrillators.

Two applications of capacitors

battery potential, charge, positive plate, negative plate, neutral

When batter terminals are connected to the initially uncharged capacitors, the _________________ moves a small amount of ______ of magnitude Q from the ______________ to the ______________. The capacitor remains _______ but with charges +Q and -Q residing on opposite plates.

Parallel-plate capacitor

A system composed of two identical parallel-conducting plates separated by a distance.

σ

Symbol that represents the surface charge density on one plate of the capacitor

E = σ/ε0

Formula for the magnitude of the Electric field in the space between the parallel plates of the capacitors

directly proportional

The magnitude of the capacitor’s Electric field is _____________________ to the charge.

The charges remain on the surfaces of the capacitor plates

The charge separation in the capacitor shows that….

Yes, it is true

Is it true that the electric field lines in the parallel-plate capacitor begins with the positive charges and ends with the negative charges.

shapes, sizes, charge, applied voltage

Capacitors with different ______ and _____ store different amounts of ______ for the same ______________ across their plates.

C = Q/ΔV

Basic formula of capacitance

ΔV

Symbol that represents the potential difference between the two capacitor plates.

NOTE: This symbol does not represents the potential at any one point.

farad (F)

The SI unit of Capacitance

Michael Faraday

The English physicist, after whom the SI unit of capacitance was named.

1F = 1C/1V

Derived SI unit of capacitance

Gauss’s law

Use ___________ if the symmetry is present in the arrangement of conductors.

Vb - Va = - ∫ab E.dl

The formula to find the potential difference between the capacitor plates

increases, charge values, decreased distance

The electric force between the parallel capacitor plates _________ with _____________ and with the ________ between the plates.

capacitor plates, charge, store

The bigger the ________________ are, the more ______ they can _____.

area, capacitance

The larger ____ of the parallel capacitor plates, provide a larger ___________

closer, greater, attraction, charges

The ______ the capacitor plates are, the _______ the __________ of the opposite _______ on them.

distance, capacitance

The smaller ________ between the parallel capacitor plates, gives us a greater ___________.

σ = Q/A

Formula for the surface charge density on the plates of a parallel plate capacitor

E = σ/ε0

Formula for the magnitude of the electrical field between the plates of a parallel plate capacitor

ε0

Symbol that represents the constant of the permittivity of the free space

8.85×10^-12 F/m

Value of the ε0

C^2/N*m^2

Derived unit for F/m

V = Ed

Second formula to calculate the potential difference between the plates of the parallel plate capacitor

V = σd/ε0

Third formula to calculate the potential difference between the plates of the parallel plate capacitor

V = Qd/ε0Α

Fourth formula to calculate the potential difference between the plates of the parallel plate capacitor

C = Q/(Qd/ε0A)

Second formula to calculate the capacitance of the parallel plate capacitor

C = ε0(A/d)

Third formula to calculate the capacitance of the parallel plate capacitor

geometry, space

Interestingly capacitance is a function only of the ________ and what material fills the _____ between the plates of the capacitor

charge, voltage

The capacitance is independent of ______ or _______. If the charge changes, the potential changes correspondingly so that Q/V remains constant