# What is Ohm's Law?

**What is Ohm's Law?**

Ohm's Law is a fundamental principle in electrical engineering and physics, describing the relationship between voltage, current, and resistance in electrical circuits. Engineers can design safe and efficient electrical circuits by understanding this principle, while technicians can troubleshoot and repair faulty circuits. The applications are numerous, from designing and selecting circuit components to troubleshoot and identifying defective components. Understanding Ohm's Law is essential for anyone working with electrical circuits and systems.

It states the amount of electric current flowing through a circuit is directly proportional to the voltage applied to the course and inversely proportional to the potential of the circuit's resistance. This relationship can be expressed mathematically as I = V/R, where I is the current, V is the applied voltage, and R is the resistance of the circuit.

Yjr formula applies to both DC (direct current) and AC (alternating current) circuits, although AC circuits require some modification due to the varying direction and magnitude of the current. In an AC circuit, the voltage and current vary sinusoidally with time, but the relationship between voltage, current, and resistance remains the same.

One practical application is designing electrical circuits and selecting circuit components. By understanding the relationship between voltage, current, and resistance, engineers can choose the appropriate components for a given application to ensure the circuit operates within a safe range of voltages and currents. For example, suppose a high voltage is applied to a circuit with low resistance. In that case, the resulting current could be dangerously high and potentially damage the circuit or electrical devices connected to it. Similarly, if the resistance in a circuit is too high for a given voltage, the current may be too low to power the intended electrical devices.

Another practical application is in troubleshooting electrical circuits. By measuring the voltage and current at various points in the circuit and applying Ohm's Law, engineers and technicians can identify potential problems and isolate faulty components. For example, if the voltage supplied to a device is too low, but the resistance of the circuit is unchanged, the current will also be too low, and the device may not function correctly. Using Ohm's Law to analyze the circuit, the technician can determine which component is causing the problem.

To better understand Ohm's Law, defining a few key terms is essential. Voltage, also known as electric potential, is a measure of the potential energy of an electrical circuit, expressed in volts. Current is the flow of electric charge through a circuit, measured in amperes. Resistance is a material's opposition to the flow of electric current, measured in ohms. The conductor's cross-sectional area, the conductor's length, and the conductor's temperature can all affect resistance.

An example in action is a simple circuit consisting of a battery, a resistor, and a light bulb. If the voltage supplied by the battery increases, the current flowing through the circuit will also increase, causing the light bulb to glow brighter. If the resistance of the circuit is increased by adding another resistor, the current flowing through the circuit will decrease, causing the light bulb to dim. Engineers can control the light bulb's brightness by manipulating the circuit's voltage, resistance, and current.

Three formulas can be derived from the ohm s law equation: I = V/R, V = IR, and R = V/I. These formulas can solve a wide range of problems involving electrical circuits. To solve a problem, determine which values are known and which are unknown. Then, select the appropriate formula and rearrange it to solve for the unknown value. Be sure to use consistent units throughout your calculations to avoid errors.

Ohm's Law regarding electromotive force (EMF) and internal resistance can also be expressed. The EMF is the voltage supplied by a voltage source, such as a battery, and the internal resistance is the resistance of the voltage source itself. Therefore, the EMF and internal resistance equation is I = EMF / (R + r), where r is the internal resistance.

Finally, an analogy of water flow in pipes can explain the concept of Ohm's Law. Just as the amount of water flowing through a pipe is directly proportional to the pressure (voltage) applied and inversely proportional to the resistance (pipe diameter) of the pipe, the amount of electric current flowing through a circuit is directly proportional to the voltage applied and inversely proportional to the resistance of the circuit.

**What is the example of Ohm's Law?**

An example in action is a simple circuit consisting of a battery, a resistor, and a light bulb. If the voltage supplied by the battery increases, the current flowing through the circuit will also increase, causing the light bulb to glow brighter. Conversely, if the resistance of the circuit is increased by adding another resistor, the current flowing through the circuit will decrease, causing the light bulb to dim.

**What are the three formulas in Ohm's Law?**

The three formulas are I = V/R, V = IR, and R = V/I. These formulas can solve a wide range of problems involving electrical circuits.

**How do you use it to solve problems?**

To solve a problem, determine which values are known and which are unknown. Then, select the appropriate formula and rearrange it to solve for the unknown value. Be sure to use consistent units throughout your calculations to avoid errors.

**What is Ohm's Law as a formula?**

It can be expressed mathematically as I = V/R, where I is the current, V is the applied voltage, and R is the resistance of the circuit.

**Three Examples of how Ohm's Law can resolve electrical problems.**

**Calculating Current**

Ohm's law states that the current flowing through a circuit is directly proportional to the voltage applied across the circuit and inversely proportional to the resistance of the circuit. The equation for Ohm's law is I = V/R, where I is the current in amps, V is the voltage in volts, and R is the resistance in ohms. This means that if you know the values of any two of these variables, you can use Ohm's law to calculate the third variable.

In this example, we know the resistance of the circuit (10 ohms) and the voltage applied across it (5 volts), so we can use Ohm's law to calculate the current flowing through the circuit. Plugging these values into the equation, we get I = 5/10 = 0.5 amps. So the current flowing through the circuit is 0.5 amps.

**Calculating Voltage**

Similarly, Ohm's law can be used to calculate the voltage across a circuit if you know the current flowing through the circuit and the resistance of the circuit. The equation for this is V = IR, where V is the voltage in volts, I is the current in amps, and R is the resistance in ohms.

In this example, we know the resistance of the circuit (20 ohms) and the current flowing through it (2 amps), so we can use Ohm's law to calculate the voltage across the circuit. Plugging these values into the equation, we get V = 2 x 20 = 40 volts. So the voltage across the circuit is 40 volts.

**Calculating Resistor Values**

Ohm's law can also be used to calculate the resistance value of a resistor needed in a circuit. In this example, we want to calculate the resistance value of a resistor that will allow a desired current to flow through a circuit with a given voltage.

The equation for this is R = V/I, where R is the resistance in ohms, V is the voltage in volts, and I is the current in amps. In this case, we have a circuit with a voltage of 12 volts and a desired current of 0.5 amps. Plugging these values into the equation, we get R = 12/0.5 = 24 ohms. So a resistor with a resistance value of 24 ohms will allow a current of 0.5 amps to flow through the circuit with a voltage of 12 volts.

**Who was Georg Ohm?**

Georg Ohm was a physicist and mathematician who was born in Germany in 1789. He studied at the University of Erlangen and then taught mathematics at the Jesuit Gymnasium in Cologne. In 1817, he became a professor of physics at the University of Berlin, where he began his research on electricity and magnetism.

At the time, there was a lot of confusion and disagreement about the nature of electricity and the relationship between electrical current, voltage, and resistance. Ohm's breakthrough came in 1827, when he published a paper entitled "The Galvanic Circuit Investigated Mathematically." In this paper, he presented his now-famous law that describes the relationship between these three electrical properties: current, voltage, and resistance. This law is now known as Ohm's Law.

His ground-breaking Law states that the current flowing through a conductor between two points is directly proportional to the voltage applied across it and inversely proportional to the resistance of the conductor. This law has important implications for the design and analysis of electrical circuits, and is now a fundamental concept in electrical engineering.

Ohm's other major contributions to science include the development of the concept of electromagnetic potential, which is a measure of the electrical potential energy of a charged particle, and the introduction of the term "conductor" to describe materials that allow electrical current to flow freely through them.

Ohm's work was not immediately recognized as groundbreaking, and it was only in the years after his death in 1854 that his contributions to science were fully appreciated. Today, he is remembered as one of the pioneers of electrical engineering, and his name is still widely recognized in the scientific community.

According to Ohm, he determined experimentally that potential energy current in resistive circuit points is directly proportional to its applied voltage and inversely proportional to its resistance. This is what is known as Ohm's Law.