Ohm's Law is a fundamental principle in electrical engineering and physics, named after the German physicist Georg Simon Ohm, who first formulated it in the 1820s. It describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. Ohm's Law can be expressed mathematically as:
V = I * R
Where:
V is the voltage across a circuit element (measured in volts, V).
I is the current flowing through the circuit element (measured in amperes, A).
R is the resistance of the circuit element (measured in ohms, Ω).
In simple terms, Ohm's Law states that the voltage across a resistor is directly proportional to the current flowing through it, and the constant of proportionality is the resistance. This relationship is linear, which means that if you double the voltage applied across a resistor, the current flowing through it will also double, assuming the resistance remains constant.
Additionally, Ohm's Law can be rearranged to calculate other parameters when two out of the three are known. For example:
I = V / R (to calculate current)
R = V / I (to calculate resistance)
It is important to note that Ohm's Law applies specifically to ohmic resistors, meaning that the resistance of the circuit element remains constant over the range of applied voltages and currents. In reality, some elements like diodes, transistors, and capacitors do not obey Ohm's Law as their resistance or impedance varies with voltage or current. However, for ohmic resistors, Ohm's Law serves as a foundational principle for understanding and analyzing electrical circuits.