H1 - use of electrical components in series and parallel circuits

series circuit

• components connected end to end, forming a single path for current

• current is same through all components

• total resistance - sum of each resistance - same with voltage

parallel circuits

• components are connected across separate branches, each having its own path

• voltage across is the same

• total current - sum of currents through each branch

• if one component fails, the others continue working

cells , batteries , power packs

• produces voltage using chemical energy ( increases voltage )

• battery 0 2 or more cells in series ( higher voltage than a single cell)

ammeter

measures current in amps

connected in series

voltmeter

• measures voltage

• connected in parallel with component

lamps

• produces light by heating a filament

• series - each lamp shares the voltage - dimmer if more lamps are added

• parallel - full voltage for each lamp - brightness stays the same

resistors

• restricts the flow of current ( ohms )

• used to protect other components from high current

thermistors

• Resistance changes with temperature

• used in temperature sensors

• provides accurate temperature measurements by varying its resistance with temperature changes

light dependant resistors

• resistance changes with light intensity

• bright light - low resistance

• darkness - high resistance

• example ( light sensors )

diodes

• allows current to flow in 1 direction only

• LEDS (light-emitting diodes )

• emits light when an electric current passes through it

• photodiodes - generate current or change resistance when exposed to light ( cameras , safety devices )

switch

• controls the flow of current by operating or closing the circuit

• used to open or close a circuit - switch

• closed switch - circuit complete - current flows

• open switch - circuit broken - no current flows

• used to turn circuit on / off for safety