What is ohm's law
I = V / R
Here, I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. R in this relation is constant, independent of the current. Ohm's law is an experiential relation which precisely defines the conductivity of the vast majority of electrically conductive materials over many orders of magnitude of current. German physicist Georg Ohm published this law in 1827 wherein measurements of applied voltage and current through simple electrical circuits containing various lengths of wire is defined. The law is named after his name and known as “Ohm’s Law”.
Understanding Ohm's Law by Triangle Form
Three equivalent expressions of Ohm's law are used interchangeably in circuit analysis. The interchangeability of the equation may be represented by a triangle, where V (voltage) is placed on the top section, the I (current) is placed to the left section, and the R (resistance) is placed to the right. The divider between the top and bottom sections indicates division. V, I, and R are arranged in triangle form as follows:
In order to know the value of R, we have to know the value of V and I as below:
In order to know the value of I, we have to know the value of V and R as follows:
In order to know the value of V, we have to know the value of I and R as follows:
Analyzing Ohm’s Law by a simple circuit
We can understand the relation between voltage, current and resistance by analyzing a simple circuit as below:
Here, battery is the source of voltage and the electric bulb load is the source of resistance. In this circuit, we can determine the value of any one source if we know the value of two other sources. In this way, we can know all three values (voltage, current and resistance) by applying Ohm’s law.