Electric Charge Electric charge is a fundamental property of matter and is carried by particles like electrons and protons. Charge comes in two types: positive...
Electric charge is a fundamental property of matter and is carried by particles like electrons and protons. Charge comes in two types: positive and negative. The charge carried by a single electron or proton is an extremely small unit called the elementary charge, denoted by the symbol e.
The law of conservation of charge states that the total charge in an isolated system remains constant; it can neither be created nor destroyed, only transferred between objects.
Materials can be classified as conductors or insulators based on their ability to allow the flow of electric charge. Conductors like metals have a high concentration of free electrons that can move through the material, allowing charge to flow easily. Insulators like plastics and ceramics have tightly bound electrons that cannot move freely, preventing charge flow.
Electric current is the rate of flow of electric charge through a conductor. The conventional direction of current is taken as the flow of positive charges, even though in metals the charge carriers are negatively charged electrons moving in the opposite direction.
Current is measured in amperes (A), where 1 ampere is equal to the flow of 1 coulomb of charge per second.
I = Q / t
Where I is the current in amperes (A), Q is the charge in coulombs (C), and t is the time in seconds (s).
Problem: A charge of 10 coulombs flows through a wire in 2 seconds. Calculate the current.
Solution:
Electrical circuits use standardized symbols to represent components like batteries, resistors, and switches. Circuit diagrams depict the connections between components, with straight lines representing conductors and the flow of current.
By understanding these fundamental concepts of charge, current, and basic circuit elements, students can build a strong foundation for further exploration of electrical phenomena and applications in A Level Physics.