What is the definition of Electrical Resistance & what is Ohms Law?
Electrical Resistance is illustrated at left courtesy of Carson Dunlop. Electrical resistance is measured in Ohms and is related to Watts and Volts by the simple equations we show here: Watts = Volts 2 / Ohms Current (Amps) = Potential (Volts) / Resistance (Ohms) Electrical resistance can be thought of as how easily electricity flows through a material. Where resistance is high more effort is needed. A smaller-diameter electrical wire has more resistance to electrical flow than a larger-diameter wire. A reason that the light bulb filament has high resistance is that it is very small in diameter. Beginning with Thomas Edison, researchers discovered that if resistance in a wire is high enough the wire will get hot enough to glow (produce light) or even to start a fire (which is why the inside of an incandescent light bulb is a vacuum – to deny oxygen and thus protect the filament from simply burning up). Georg Ohm’s Law, first published in 1827, I = V / R tells us that the current (amps)
