: 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.
Voltage is expressed as a signed number of Volts (V). The voltage gradient in Volts per metre is proportional to the force on a charge. Voltages are often given relative to earth or ground which is taken to be at zero Volts. A circuit's earth may or may not be electrically connected to the actual earth. The voltage between two points is also given by the charge present between those points in Coulombs divided by the capacitance in Farads.