Ohm’s Law Formula

Definition Of Ohm’s Law

Ohm's Law relates the current flowing through a conductor between two points in direct proportion with the voltage across the two points, provided the temperature and properties of the conductor's material are kept constant.

Mathematically the formula  is expressed as :

 V=IR

Here,

• V = voltage across the conductor (in volts, V),

• I = current flowing through the conductor (in amperes, A),

• R = the resistance of the conductor (in ohms, Ω).

This definition highlights the linear relationship between voltage and current in a conductor, assuming the resistance remains constant.

Understanding Ohm's Law: The Cornerstone of Electrical Circuits

Ohm's Law is the very basis of electrical engineering and physics, which enables a fundamental relationship in voltage-current-resistance in any electrical circuit. It is named after the German physicist Georg Simon Ohm. It forms one of the important relations employed in the design and analysis of electrical systems ranging from simple circuits to complex electronic devices.

Understanding Components

• Voltage (V): The voltage between two points is the electric potential difference between those two points. It could also be explained as the "push" exerted by the electric charges through a conductor. Voltage is expressed in volts.

• Current: Current means the rate of flow of electric charges through a conductor. It means the flow of electrons, and amperes are the units in the measurement of current.

• Resistance: This is the property of the component that resists or opposes the flow of current through a circuit. The material that determines this includes the length and cross-sectional area of the conductor. Its unit is ohm or Ω.

Ohm's Law Formula

The Ohm's law formula or the potential difference formula is used to find the calculation of resistance, current, and voltage in any given circuit if any two of these quantities are given.

Following are some sample problems on Ohm's Law along with their solutions:

Problem 1: Basic Voltage Calculation

Question: A resistor is rated for a resistance of 10 Ω and is carrying a current of 2 A. What is the voltage across the resistor?

Solution: Using Ohm's Law: V= I×R

Substitute the values: V = 2 A×10 Ω              

                                    V = 20 V 

Thus, the voltage across the resistor is 20 V.

Problem 2: Current Calculation

Question: If a resistor of 5Ω is connected to a voltage source of

15V, what is the current flowing through the resistor?

Solution: Using Ohm's Law  I=VR

Substitute the values:    I=15V5

                                     I= 3A​

So, the current flowing through the resistor is 3A.

Problem 3: Resistance Calculation

Question: A circuit has a voltage of 12V and the current flowing through it is 4A. What is the resistance of this circuit?

Solution: Using Ohm's Law: R=VI

​Substitute the values: R=12V4A

                                 R=3A

 So, the resistance in the circuit is 3Ω

Thus, the resistance of the circuit is The law of Ohm remains basic in electrical engineering, providing reasons for insight into how circuits work. Knowledge of the relationship between voltage, current, and resistance enables the engineer or technician to design, analyze, and perform some troubleshooting in electrical systems.

 

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