2.2 Current: Flow of Electric Charge

Introduction to current: Current is a fundamental concept in electricity that refers to the flow of electric charge in a circuit. It is denoted by the symbol "I" and is measured in amperes (A). Current represents the rate at which electric charges, typically electrons, move through a conductor.

Types of current: There are two types of current: direct current (DC) and alternating current (AC). In DC, the flow of electric charges is in one direction, while in AC, the direction of current changes periodically. DC is commonly produced by batteries and power supplies, while AC is the type of current supplied by electrical grids.

Current measurement: Current can be measured using a device called an ammeter. An ammeter is placed in series with the circuit, and it measures the amount of current flowing through the circuit. The ammeter provides a numerical value indicating the magnitude of the current.

Current flow in series and parallel circuits: In a series circuit, the current is the same at all points in the circuit. It flows through each component in the series without splitting. The total current entering the circuit is equal to the total current exiting the circuit. In a parallel circuit, the total current is divided among the branches based on the resistance of each branch.

Current and Ohm's Law: Current is directly related to voltage and resistance through Ohm's Law. According to Ohm's Law, the current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to its resistance. The relationship is given by the equation I = V/R, where I is the current, V is the voltage, and R is the resistance.

Understanding current and its behavior is essential for analyzing and designing electric circuits. It helps us determine how charges move through conductors and how different components affect the flow of current.