Introduction to Electricity Electricity is a fundamental concept in physics that deals with the study of electric charges, currents, and their associated effect...
Electricity is a fundamental concept in physics that deals with the study of electric charges, currents, and their associated effects. In this article, we will explore the key principles and concepts related to electricity and electric circuits.
Electric charge is a fundamental property of matter that comes in two forms: positive and negative. Protons carry a positive charge, while electrons have a negative charge. The flow of electric charges constitutes an electric current, which is measured in amperes (A).
Potential difference, also known as voltage, is the measure of the electrical potential energy difference between two points in an electric circuit. It is measured in volts (V) and is the driving force that causes charges to flow through a circuit.
Resistance is a measure of the opposition to the flow of electric current in a conductor. It is measured in ohms (Ω). Ohm's Law describes the relationship between current (I), potential difference (V), and resistance (R): V = IR.
In a series circuit, components are connected end-to-end, and the current remains constant through each component. The total resistance is the sum of the individual resistances, and the potential difference across the circuit is the sum of the potential differences across each component.
In a parallel circuit, components are connected in separate branches, and the potential difference across each component is the same. The total current is the sum of the currents through each branch, and the total resistance is less than the smallest individual resistance.
Electrical power is the rate at which electrical energy is transferred or consumed in a circuit. It is calculated using the formula P = IV or P = I2R. Electrical energy is the product of power and time (E = Pt) or the product of charge and potential difference (E = QV).
Domestic electrical systems use safety features like fuses and earth wires to protect against electrical hazards. Fuses are designed to melt and break the circuit when the current exceeds a safe level, while earth wires provide a low-resistance path for electrical currents to the ground in case of a fault.
Static electricity is the build-up of electric charges on the surface of an insulator due to friction or other processes. It creates an electric field and can lead to electrostatic forces between charged objects, which can cause attraction or repulsion.
Problem: Calculate the current flowing through a 120 Ω resistor connected to a 12 V battery.
Solution:
Therefore, the current flowing through the 120 Ω resistor is 0.1 A (or 100 mA).
By understanding these fundamental concepts, you can better comprehend the behavior of electric circuits and the various phenomena associated with electricity.