Ohm's law

Krunal Gandhi


Ohm's law
Ohm's law is used to calculate the relationship between voltage, current, and resistance in the electrical circuit.it is named after German physicist George Simon Ohm.

Statement-

Ohm's law states that the current flowing through a conductor between two points is directly proportional to the voltage across two points, provided the temperature and all other factors remain constant. 

                          I ∝ V   ⇒   V ∝ I  ⇒ V = IR

Where, 
I – Current flowing through the conductor (Amp) 
V – Voltage across the conductor (volts)
R - Resistance of the conductor (ohms)
R is a  proportionality constant which is a property of the conductor. It should be kept constant during experiments of Ohm's law. But the variation of temperature affects the value of resistance. So during the experiments of Ohm's law, the temperature is considered Stable to keep the resistance constant.

Applications-

  • There are many applications of the Ohm's law
  • The principle of Ohm's law is used in Electric heater. 
  • The calculation of resistance is done by Ohm's law while designing circuit.
  • Measuring the value of unknown resistance by using resistance bridge circuits.
  • Domestic Fan Regulator
  • In electronic circuits, where intentional voltage drop is necessary to provide specific voltage through different electronic elements.

Limitations-

  • Unilateral devices have not the same voltage and current relationship for both directions of the current. Due to this ohm’s law is not used for unilateral devices like a diode, transistor etc. 
  • Non-linear elements do not have current exactly proportional to the applied voltage.so the value of resistance changes with changed voltage and current value. Due to this ohm’s law is not used for Non-linear elements like a thyristor and electric arc etc. 



Ohm’s law wheel [Ohm’s Wheel]


Ohm’s Wheel is a collection of 12 different formulas which helps to calculate Voltage, Current, Power, and Resistance.

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