Lernkarten

Karten 474 Karten 7 Lernende Deutsch Grundschule 12.01.2015 / 21.01.2020 Keine Angabe
334 Exakte Antworten 87 Text Antworten 53 Multiple Choice Antworten

Atom besteht aus

Protons (+), neutrons and electrons (-) => protons and neutrons forms the nucleus around the electrons move very rapidly in certain shells

Th electrons in the outermost shell calls

valence electrons

Heat effect

electrons move in in one direction = voltage => While traveling on their way through the conductor => these oscillations produce heat

Ions?

are the carrier of electrical charge in liquid or gases

conductors

are metals (aluminum/cooper, silver, gold)

some liquids also belong to teh group of conductors => different to metals?

no electrons but ions move

Semiconductors

have a very weak conductivity => after a certain contamination a certain voltage is attained

conductivity

conductivity = the electrons in the outermost shell of the material determine its electrical conductivity

Isolators (Insulators)

have many electrons in the outermost shell (3 to 8) => no free electrons => The electrical resistance is almost infinite

effect of light

Bohrs model => greater the distance of the electron from the core, the greater is the energy level of the electron => quantum jump from on to another orbit

=> The light effect by the quantum jump can be produced withe different material

=> fall back to a lower orbit and emit photons of light, which can be seen as visible light

Light Bulb

Lizenzierung: Keine Angabe
Inside: either a cave or low pressure inert gas => The heating of the filament causes it to emit light and the vacuum/inert gas prevents the filament from burning out due to evaporation

Fluorescent lamp

Lizenzierung: Keine Angabe
the glass tube, which contains two electrodes at each end and a gas => both electrode filaments very quickly and emits electrons to ionize the argon gas inside the tube ==> ignites the gas with a very high voltage

Light emitting diode (LED)

two semiconductors layers=> low voltage electrons are moved from one semiconductor material to another semidconductor material => In the penetration (Durchdringung) of the other semiconductor material light photons are generated ==> High efficiency low pr

Generator

a magnetic field rotates inside a conductor loop and produces an alternating voltage => When a load is connected to the conductor loop, an AC results

Battery

the chemical effect of electricity is used to produce voltage => two different solid conductors are submerged on a liquid conductor

Piezo Effect

Lizenzierung: Keine Angabe
a changing mechanical load => crystals produce a voltage proportional to the change in geometric dimension => this is a reversible process => clocks, watches

consequence of static charching during flight after teh flight?

between aircraft fuselage can generate large sparks (Funken ) => can affect communications and navigation systems

Thermocouple

Lizenzierung: Keine Angabe
two different metals are connected and heated at the junction ==> very low voltage is produced

Voltage

Spannung (V) the relation of the work (w) necessary to move a charge (lauding) to the magnitude of this electrical charge (Q)

=> $$U = {W \over Q}$$

=> pole with a shortage of electrons is called positive (+)

=> pole with a surplus of electrons is called negative (-)

Current

der Fluss = Spannung => (A) => is directed movement of electrical charge => rleation quarge to time

=> $$I = {Q \over t}$$

=>Current flow must be from the electron superplus (-) to the lectron shortage (+)

Resistor

Wiederstand (R) => electrons exchange their energy => in this way, electrical energy is transformed into heat

Depends on:

a) resistance of the material

b) teh length

c) section

Types of resistors

a) Evaporated carbon resitor => thinner layers provide greater resistance

b) Metal resistor: alloys are wounded around a small porcelain tube => the cros section of the conductor and the length of the wire

c) Variable esistor => manually controllable = potentiometer

d) Temperature Dependence => 3 types: PTC, constant and NTC resistance of every resistor changes with temperature

potentiometer

Variable resistor => manually controllable resistor z.B. VHF

Temperature Independent Resistor

The value of the resistor remains constant with the temperature change => used as a balancing resistor in temperature measurement circuit

PTC

Positive Temperature coefficient Resistor: resistance increase with increasing temperature

NTC

Negative Temperature Coefficient Resistor: resistance decreases as the temperature increases => 2 Drähte ( innen + aussen Halbleitermaterial, ganz aussen die Masse) wenn es heisser, nimmt Resistance ab und wandert an die Masse = electrical Fluss = Signal

Electrical Circuit (DC)

a closed circuit => DC electrical circuit => No change in the amount of current over time in a DC circuit = I = constant = no change in the direction of the current

Electrical Circuit (AC)

AC current means a change in the direction of the current

Toggle switch

Lizenzierung: Keine Angabe
switch multiple independent circuit

Ganging ?

Lizenzierung: Keine Angabe
switch multiple independent circuit => Connection over many switches !!