Electric Resistance

Electric resistance R is a measure of how much an object or substance opposes the flow of electric current through it.  In order to overcome the resistance and get the current to flow a higher voltage will be required. Resistance is measured in Ohms, represented by \(R\) and has a symbols \(\Omega\).  The resistance of an object depends on its size, shape, material, and temperature.

The resistance of a material can be calculated using Ohm's Law, which states that the current flowing through a conductor is directly proportional to the voltage across it, and inversely proportional to its resistance.

 

Electric resistance formula
\(\large{  R = \frac{V}{I} }\)
Symbol	English	Metric
\(\large{ R }\) = resistance	\(\large{\Omega}\)	\(\large{\frac{kg-m^2}{s^3-A^2}}\)
\(\large{ V }\) = voltage	\(\large{V}\)	\(\large{\frac{kg-m^2}{s^3-A}}\)
\(\large{ I }\) = current	\(\large{I}\)	\(\large{\frac{C}{s}}\)

 

Electric resistance formula
\(\large{  R = \frac{V^2}{P} }\)
Symbol	English	Metric
\(\large{ R }\) = resistance	\(\large{\Omega}\)	\(\large{\frac{kg-m^2}{s^3-A^2}}\)
\(\large{ V }\) = voltage	\(\large{V}\)	\(\large{\frac{kg-m^2}{s^3-A}}\)
\(\large{ P }\) = power	\(\large{P}\)	\(\large{\frac{kg-m^2}{s^3}}\)

 

Electric resistance formula
\(\large{  R = \frac{P}{I^2} }\)
Symbol	English	Metric
\(\large{ R }\) = resistance	\(\large{\Omega}\)	\(\large{\frac{kg-m^2}{s^3-A^2}}\)
\(\large{ P }\) = power	\(\large{P}\)	\(\large{\frac{kg-m^2}{s^3}}\)
\(\large{ I }\) = current	\(\large{I}\)	\(\large{\frac{C}{s}}\)