Electricity Flashcards
What is POTENTIAL DIFFERENCE?
Energy supplied per unit charge.
What is EMF?
Chemical energy transferred to electrical energy per unit charge.
What is a KILOWATT HOUR?
Energy used in one hour of appliance being switched on. Unit of energy.
kWh = (Watts x hour) / 1000
What is RESISTANCE?
Potential difference across a component per current.
What is MEAN DRIFT VELOCITY?
Average displacement of an electron along a wire per second. They move slowly in one direction, constantly colliding with the lattice and transferring energy.
What is OHM’s LAW?
Current is proportional to voltage and inversely proportional to resistance.
What is a SEMI CONDUCTOR?
A component that acts as an insulator at low temperatures and a conductor at high temperatures.
What is the THRESHOLD VOLTAGE?
The minimum amount of voltage needed for a semi conductor to conduct a current.
What does a POTENTIAL DIVIDER do?
Allows for a circuit to achieve a suitable voltage by dividing it across two resistors.
What is RESISTIVITY?
A property that describes the extent to which a material opposes flow of current.
What is FIRST KIRCHOFF’S LAW?
At a junction in an electrical circuit, the sum of currents flowing into the junction is equal to the sum of currents flowing out of the junction.
Therefore, if current flows into a junction, the current across all the components in that section will be the same.
