E Flashcards
Potential difference
The change in potential energy per coulomb between two points, due to the charge doing work on circuit components
EMF
The change in electrical potential energy per coulomb between two points, due to work being done on the charge, for example by a battery or power supply
Volt
The potential difference between two points when a 1C charge passing between the points expériences a change in electric potential energy of 1 J
Charge of an electron
1.6x10^-19
Kinetic energy of electrons
When a potential difference accélérâtes a charged particle, the energy transferred is equal to the kinetic energy gained by the particle (usually an electron)
Ohms law
For an ohmic conductor at a constant temperature, the current is directly proportional to the potential difference across it
Electrical power
Power is the rate at which energy is transferred, used or transformed, measured in joules per second or watts
Kilowatt hour
A unit of energy equal to one kW of power usage for 1 hour ie 3.6 million joules. Often used to calculate household energy bills
Kirchhoffs second law
The total emf around a closed loop circuit is equal to the sun of potential drops (potential differences) around that loop. This is due to conservation of energy
current
rate of flow of charged particles
the ampere
1 coulomb of charge passing a point in one second
conventional current
current flows from a point of high potential energy to a point of low potential. this is normally from the positive terminal to the negative terminal
electron flow
in metals, as electrons are negatively charged, electron flow is from the negative terminal to the positive terminal
kirchoffs first law
the sum of currents entering a junction must be equal to the sum of currents leaving the junction
conservation of charge
charge can neither be created nor destroyed: the net quantity of charge in the universe, ie the amount of negative charge plus positive charge, must remain constant. This is the same for any closed system
