: a very large amount or number: an amount that is much greater than what is necessary. A plethora of books have been written on the subject. a plethora of information. [+] more examples [-] hide examples [+] Example sentences [-] Hide examples. a very large amount or number: an amount that is much greater than what is necessary. A plethora of books have been written on the subject. a plethora of information. [+] more examples [-] hide examples [+] Example sentences [-] Hide examples.
Ohm's law defines the relationship between the voltage, current, and resistance in an electric circuit: I = V / R. The current is directly proportional to the voltage and inversely proportional to the resistance.
This is called electrical resistance, and is measured in the unit ohm. The resistance can be calculated with Ohms law, when the current is known and the voltage drop is measured: The resistance of a resistor is dependent on its material and shape. Some materials have a higher resistivity, causing a higher value.