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: '''LEDs''' have a low [[Electrical Resistance|resistance]] in one direction and [[emit]] [[light]] but a very high [[Electrical Resistance|resistance]] in the reverse direction and do not [[emit]] [[light]].
: '''LEDs''' can be used to change an [[Alternating Current|alternating current]] into a [[Direct Current|direct current]].
===IV Graph===
{| class="wikitable"
|[[File:IVGraphDiode.png|center|400px]]
|}
====Description====
The [[IV Graph]] for an '''LED''' shows that:
*For a positive [[Potential Difference|potential difference]] the [[Electrical Current|current]] increases rapidly with an increase in [[Potential Difference|potential difference]]
*For a negative [[Potential Difference|potential difference]] the [[Electrical Current|current]] remains negligible and does not increase as the [[Potential Difference|potential difference]] becomes larger.
====Explanation====
: The [[Electrical Resistance|resistance]] of an '''LED''' is very low for [[Electrical Current|current]] in the forward direction and very high in the back direction.
====Obtaining the IV Graph====
{| class="wikitable"
|-
|[[File:DiodeIVGraphCircuit.png|center|300px]]
| style="height:20px; width:300px; text-align:left;" |
#Connect an [[ammeter]] in [[Series Circuit|series]] with the '''LED''' to measure [[Electrical Current|current]] through the '''LED'''.
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the '''LED''' to measure the [[Potential Difference|potential difference]] across it.
#Use a [[Variable Resistor|variable resistor]] in [[Series Circuit|series]] with the '''LED''' to vary the [[Potential Difference|potential difference]] across the '''LED'''.
#Start with a [[Potential Difference|potential difference]] of zero and increase the [[Potential Difference|potential difference]] by an interval of 0.2V up to 2V.
#Recording the reading on the [[voltmeter]] and [[ammeter]].
#Reverse the connections on the [[battery]] and repeat steps 4 and 5 to find the I-V relationship for negative [[Potential Difference|potential difference]] and [[Electrical Current|current]].
|}
===References===
====AQA====
:[https://www.amazon.co.uk/gp/product/0008158770/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158770&linkCode=as2&tag=nrjc-21&linkId=ec31595e720e1529e49876c3866fff6e ''LED (light emitting diode), page 52, GCSE Physics; Student Book, Collins, AQA '']
:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Light-emitting diodes (LEDs), page 43, GCSE Physics, Hodder, AQA '']
:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Light-emitting diodes (LEDs), page 60, GCSE Combined Science Trilogy; Physics, CGP, AQA '']
:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Light-emitting diodes (LEDs), page 62, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']
:[https://www.amazon.co.uk/gp/product/1471851354/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851354&linkCode=as2&tag=nrjc-21&linkId=9012a0d354024419214fb3ad5ac44ba0 ''Light-emitting diodes (LEDs), pages 293, 298, GCSE Combined Science Trilogy 1, Hodder, AQA '']
:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Light-emitting diodes (LEDs); circuit symbol, page 38, GCSE Physics, Hodder, AQA '']
:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Light-emitting diodes, pages 52, 57, GCSE Physics; Third Edition, Oxford University Press, AQA '']
====OCR====
:[https://www.amazon.co.uk/gp/product/0198359837/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359837&linkCode=as2&tag=nrjc-21&linkId=3c4229e8b023b2b60768e7ea2307cc6f ''Light-emitting diodes (LEDs), pages 106-107, Gateway GCSE Physics, Oxford, OCR '']