ohmic and non-ohmic conductors Flashcards
in ohmic components which two variables are directly proportional
current and potential difference
if current and potential difference are directly proportional, what does it tell us about the resistance
it is constant
name 4 non-ohmic conductors
filament bulbs, diodes, thermistors, LDRs
why are filament light bulbs non-ohmic
current, temperature, resistance all increase
describe the relationship between current and potential difference for a diode
current only flows in one direction and has a very high resistance in the other direction
describe the relationship between temperature and resistance in a thermistor
as temperature increases resistance decreases
state on use of a thermistor
thermostat
describe the relationship between light intensity and and resistance in a LDR
Light intensity increases and resistance decreses
state one use of a LDR
switching lights on when it gets dark eg. street lamps
what does ohmic mean
if as voltage across the resistor is increased, a graph of voltage versus current shows a straight line (indicating a constant resistance)
