In the year 1828, George Simon Ohm, a German scientist, derived a relationship between electric current and potential difference. He named the relation to Ohm’s law. Ohm’s Law states that at a constant temperature, pressure the current flowing through a conductor is directly proportional to the potential difference applied across it. This is true for many materials, overwide values of voltages and currents, and the conductance and resistance of electronic components made from these materials remain constant.
Mathematically,it can be written as
V α I
V = I.R
I = V/R
Where; R is the resistance of the conductor in ohms (Ω).
I is the current flowing in amperes(A)& the V is the voltage applied in volts(V).
Electrical resistance (R) – of any object is defined as the measure of its opposition to the flow of electric current. The inverse of resistance is electrical conductance. It is defined as the ease with which an electric current passes. The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S called mho). The resistance of an object depends on the material it is made of—objects made of electrical insulators example rubber tend to have very high resistance and low conductivity, whereas objects made of electrical conductors like metals tend to have very low resistance and high conductivity.
Ampere (A) – an ampere is the unit of electrical current. Ampere is defined as how many electrons pass a certain point per second. That is equal to one coulomb of charge per second, or 6.24 x 10^18 electrons/second.
Volt(V)– It is the basic unit of electromotive force in the SI and MKS systems, equal to the electromotive force, or difference in potential, that causes a current of one ampere to flow through a conductor having a resistance of 1ohm.
Watt (P) – is the basic unit of electric, mechanical, or thermal power in the SI and MKS systems, It is equal to one joule per second or 10 ergs per second (of a horsepower).
Ohms Law triangle the magical V I R triangle can be directly used to calculate all formulations of ohm’s law. Use a finger to hide the value is to be calculated. Then the other two values show how to perform the calculation.
Ohm’s Law formula PaiChart
For a better understanding of the relation between various parameters, we can combine all the equations used to find the voltage, current, resistance and power into a simple Ohm’s Law pie chart as shown below.
Ohm’s law calculator works on the same set of equations. Providing the two values third can be calculated easily by using ohms law equations. The figure given below shows the ohms law formula.
Current Power Resistance