Ohm's law

Ohm law mainly represents the relationship among current, resistance, and voltage. This law has importance in electrical engineering. If we say that without ohm's law electrical field is nothing so it will not be wrong. Because this law is consists of voltage, current, resistance, and power that is the main quantity of electrical field without these it is nothing. These are also called electrical quantities. Ohm's law states that " if the voltage increases, current also increases with constant resistance. By this law, it can be concluded that voltage is directly proportional to current and inversely proportional to resistance. Remember that current depends upon voltage, not voltage-dependent upon the current. if we increase the value of voltage then-current increases, but resistance should remain constant. Voltage is like force or pressure on charges to flow and the resistance resists these charges to flow. This law can be expressed mathematically as below 

Ohm's law triangle shows the relation between voltage, current, and resistance

                        V ~ I     or    V = IR 

 Ohm's law is represented by a German physicist and mathematician "Georg Simon Ohm". This law is used to find and evaluate the voltages, current flow, and power in different types of circuits, devices, equipment, and machines. Ohm's law is still very useful. It has some limitations for applying ohm's law that is as follow:

• This law applies to all linear circuits and cannot be used in nonlinear circuits. A linear circuit is one in which circuits parameters(resistance, capacitance, etc ) remain constant and do not change.
• It does not apply to unilateral networks.

Unilateral circuits are those that consist of the diode, transistors, etc. There are not all conductors that need to obey ohms law.  Power can be evaluated with the help of ohm's law;  

                                     P= VI

With the help of ohm's law, any quantity from voltage, current resistance, or power can be found. If any two quantities are known, the remaining third quantity can be found with the help of V=IR or P=VI.

There are meters are available to practically find these quantities values. A digital multimeter is a device or meter by which any electrical quantity can be measured. This meter is consists of an ohmmeter for resistance, a voltmeter for voltage, and an amperemeter for current.

Voltage and current has a linear relation and can be seen below

This graph shows that voltage and current has a linear relation