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electric charge

positive charge:
- protons (atomic nucleus)
- (kat-) ions (ionized metal, ionized hydrogen, ionized gases... )

negative charge:
- electrons (atomic envelope)
- (an-) ions (remaining acid ions, ...)

force of repulsion between like charges
force of attraction between different charges

elementary charge, charge of an electron

power

the rate at which work is performed or energy is converted
Electric power: the rate at which electrical energy is transferred by a circuit

symbol: P
unit: 1 Watt 
symbol:


formula:

Electricity

Electric charge: a property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter is influenced by, and produces, electromagnetic fields.
Electric current: a movement or flow of electrically charged particles, typically measured in amperes.
Electric field: an influence produced by an electric charge on other charges in its vicinity.
Electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.
Electromagnetism: a fundamental interaction between the magnetic field and the presence and motion of an electric charge.

speed of light
light speed

symbol: c
Value in vacuum:
c = 299,792,458 metres per second = 1 Planck unit
(Sunlight takes about 8 minutes, 19 seconds to reach Earth, but, due to refraction, scattering, gravity and so on, about 100000 years to reach the surface of the sun from it's core)

- the maximum speed in the universe
- a constant of nature
- in a medium reduces the speed of light
- different types of light wave will travel at different speeds.

Approximate values:
300,000 kilometres per second        
1,079 million kilometres per hour        
186,000 miles per second                
671 million miles per hour                
173 astronomical units per day

real animation: Speed_of_light_from_Earth_to_Moon

galvanic separation



example: Pyro- und Piezoeffekt bei Turmalinkristallen

voltage source

DC:
cell
battery (3 or more cells in series connection)
accumulator = rechargeable battery or storage battery

AC:
alternating current generator (AC generator)
power supply unit
power transformer
power adaptor

series circuit
series connection


I = constant
U = U1 + U2 + ...
R = R1 + R2 + ...

shunt circuit
parallel circuit
parallel connection

U = constant

I = I1 + I2 + ...

rectification

converter of AC to DC

current
(strength of electric current)

Def.: physival value - means the rate of flow of electric charge through the surface of the conductor (a quantity)
symbol: I
unit: ampère (the rate of one coulomb per second)
symbol: 1 A

voltage
(electrical potential)

Def: physical value (quantity) for galvanic separation
symbol: U
unit: volt
symbol: 1V


(see also: galvanic separation)

resistor (device)
resistance (value)
reluctance (magnetical resistance)
inductance (resistance of an inductor in alternating current = AC)

Def.: physical value, how strong the electric current is restricted
symbol: R
unit:      1 (Ohm)
symbol and basic units:
             
formula:
             

resistivity
(specific electrical resistance or volume resistivity)

Def: measure of how strongly a material opposes the flow of electric current
symbol: ("Rho")

unit:
         
      
or