electricity Flashcards
what is direct current
current flows in one direction when flowing in the circuit
what colour is the earth wire
yellow and green
what is alternating current
current that continually changes direction when flowing in the circuit
what does a fuse do
a fuse breaks the circuit preventing current from flowing to an appliance
what should you choose when choosing a fuse raring:
then one below it, the one above it, the lowest or the highest
you should choose the next one above than the one used. e.g. if the fuse rating is 5A then you should use 7A
what does the earth wire do
the earth wire allows the current to flow to the earth but only when the case becomes live.
what does the graph look like showing the variation between direct current and time
it should be a straight line above the time line
what does the graph look like showing the variation between alternating current and time
it should be a wavy line between the time line going top to bottom
what should the graph look like for a current-potential difference
it should be a straight line through the middle diagonally
what is the symbol for a fixed resistor
a square
what is the symbol for a variable resistor
a square with an arrow going through it diagionaly up
what is the symbol for a LDR
a square with 2 arrows at the top pointing down
what is the symbol for a thermistor
a square with a line going through it
what is the symbol for a diode
an arrow with a line at the tip
what is the symbol for a LED
an arrow with a line at the tip and 2 arrows at the top pointing away
