3.3 Electrical Terminology Flashcards
What is EMF
Electromotive force, it is the potential difference when no current flows
What is the iAcadamy definition of voltage?
Defined as the number of joules of energy per coulumb of charge.
A mesure of the difference in electrical charge between two points (potential difference)
What is current.
What is the units.
It is the number of coulombs of charge flowing through a circuit per second.
Amps or coulombs per second
What is resistance.
Opposition to the flow of electrical current.
V= IR
Giga
Mega
Kilo
Milli
Micro
Nano
Pico
Giga = 10^9
Mega= 10^6
Kilo = 10^3
Milli = 10^-3
Micro = 10^-6
Pico = 10^-12
Definition of voltage?
Number of joules of energy per coulomb of charge
What is the key difference between AC and DC
In DC the polarity does not change over time, even if the value changes
EMF
The electromotive force is a measure of the energy transferred to the circuit from other forms of energy, for example the supply.
PD
Measure of the energy transferred form electrical energy to other forms of energy when a current flows through part of a circuit.
Current
Coulombs per second.
Rate of electrical charge in a certain direction
Resistance
Opposition to flow of electrical current.
A measure of how much energy is needed to cause a current to flow. The higher the resistance, the higher the potential difference needed to obtain the same current
Conventional flow
From positive to negative, used in this course unless stated otherwise
