Changes

'''Electrical resistance''' is a measure of how much a substance impedes the flow of [[electrons]].<ref>http://www.answers.com/topic/electrical-resistance-1</ref> Resistance is represented with the symbol ''R'', it's [[SI]] unit is the [[Ohm]] (Ω).

'''Electrical resistance''' is a measure of how much a substance impedes the flow of [[electrons]].<ref>http://www.answers.com/topic/electrical-resistance-1</ref> Resistance is represented with the symbol ''R'', and its [[SI]] unit is the [[Ohm]] (Ω).

Resistance is in a circuit can be calculated by the [[voltage]] divided by the [[current]] (R = V / I).

Resistance is in a circuit can be calculated by the [[voltage]] divided by the [[current]] (R = V / I).