circuits

electrical current

flow of charge

for electrical current to flow there must be

a complete circuit

the higher the potential difference

the higher the current

potential difference is measured in

volts (V)

the higher the resistance

the lower the current

resistance

measured in ohms

in a series circuit the current is

the same all the way around

in a series circuit the total resistance is

the sum of the separate reistors

in a parallel circuit the current

is different along each path

in a parallel circuit the total resistance is

less than the smallest amount of resistors

light dependent resistor

as the light intensity increases the resistance decreases

uses of ldr - light sensors

thermistor

as the temperature increases the resistance increases

use of thermistor - temperature sensing in devices and eat generation ect..

IV graphs - ohmic resistor

directly proportional at fixed temperature

straight line through (0,0)

IV graphs - filament bulb

as the potential difference increases the resistance increases

IV graphs - diode

current only flows in one direction

resistance is very high in the reverse direction