Alternating and Direct current

which way does AC current go?

both ways constantly being reversed back and forth

how does AC current occur?

happens when we use an alternating voltage or potential difference, so a voltage/PD that fluctuates between positive and negative

what type of current does all the UK mains supply?

AC/alternating current

what is the voltage and frequency that mains supplies in the UK give?

230V and 50Hz

which way does DC current go?

charge is always flowing one way it’s either positive or negative the entire time

where is DC current found?

in cells and batteries eg. phones and calculators

how is DC current shown on an oscilloscope trace?

a straight line

how is AC current shown on an oscilloscope trace?

alternating/fluctuating waves

what is an oscilloscope?

a piece of apparatus that can be used to measure voltage and frequency of a type of current, the device has a screen where the voltage is plotted as a wave

why does AC supply show a wave?

because the current is constantly changing direction

what was the idea of conventional current?

- Historical concept: Developed before discovery of electron, that current flows from positive to negative whereas it’s the opposite

why does DC supply show a horizontal trace?

the direction of the current isn’t changing

what is rectification?

when we use a diode to convert AC from the mains to DC (eg in a battery charger)