electricity Flashcards
what direction do electrons flow
from negative to positive
what is current
rate of flow of charge. made up of electrons
what is potential difference
electrical work done by a power supply per unit of charge flowing in a circuit
what is the relationship between current and potential difference
directly proportional
what is a resistor
wire or component that charge struggles to flow through
what is the relationship between resistance and current
inversely proportional
what is a zero error
an issue with the set up/ measuring system of practical
in the required practical of resistance in a wire, why does the graph not go exactly through the origin?
other components in circuit have resistance so resistance is never at 0. it is also hard to get crocodile clips exactly at 0cm
what is an ohmic resistor
where resistance remains constant. this causes current to be directly proportional to potential difference
describe the IV graph for a fixed resistor
as potential difference increases, current also increases. directly proportional
describe the IV graph for a filament lamp
as potential difference increases, the current the current starts to increase. gradually current increases less and less each time because the filament in lamp gets hotter increasing resistance
describe and explain the IV graph for a diode
when the diode is connected the right way round then a large current flows as the potential difference increases. if connected the other way round, no current flows as resistance is so high
