Alternating Current

define alternating current

An alternating current (a.c.) is defined as a current that continuously changes its direction, going back and forth around a circuit

how are direct and alternating current represented on an oscilloscope

D.C - as a straight line near the top

A.c - a wiggle line through the graph

what is a characteristic of a.c power supply

An a.c. power supply has two identical terminals

describe the potential difference in alternating current circuits?

The potential difference between the terminals varies as a sine curve, or sinusoidally

describe the frequency in alternating current circuits?

The frequency of an alternating current is the number of times the current changes direction back and forth each second

what is mains electricity in the UK

In the UK, mains electricity is an alternating current with a frequency of 50 Hz and a potential difference of around 230 V

compare a.c and d.c current. how would you get full marks in a question like this?

If you are asked to explain the difference between alternating and direct current, sketching and labelling the graphs shown above can earn you full marks.