Ohm's law

Ohm's law is a fundamental law in electrical engineering that describes the relationship between current, voltage, and resistance in an electrical circuit. It states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, provided the temperature and other physical conditions remain constant. Ohm's law is named after the German physicist Georg Simon Ohm, who first formulated it in 1827.

The equation for Ohm's law is V = IR, where V is the voltage across the two points, I is the current flowing through the conductor, and R is the resistance of the conductor. This equation shows that the voltage across a conductor is directly proportional to the current flowing through it, and inversely proportional to the resistance of the conductor. In other words, if the voltage across the conductor is increased, the current through the conductor will also increase, provided the resistance of the conductor remains constant. Similarly, if the resistance of the conductor is increased, the current through the conductor will decrease, provided the voltage across the conductor remains constant.

Ohm's law is valid for a wide range of materials and devices, including resistors, conductors, and semiconductors. In a resistor, the resistance is constant over a wide range of voltages and currents, and Ohm's law applies exactly. In a conductor, the resistance may vary with the temperature and other physical conditions, but Ohm's law is still a good approximation for most practical purposes. In a semiconductor, the resistance may vary with the applied voltage, and Ohm's law may not apply directly. However, Ohm's law can still be used to describe the behaviour of semiconductors in some situations.

Ohm's law has many practical applications in electrical engineering. It is used to calculate the current, voltage, and resistance in circuits, and to design circuits for specific applications. It is also used to measure the resistance of a component, by measuring the voltage across it and the current flowing through it. Ohm's law is essential for understanding the behaviour of electrical circuits and is a fundamental concept in the study of electrical engineering.