: 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.
The internal resistance of a battery is generally measured by noting the change in its output voltage under different load currents. Suppose that when the battery supplies one current I1, its output voltage is V1, and when it supplies a current I2 its output voltage is V2. The internal resistance is given by R = (V1-V2)/(I1-I2)