Understanding Electric Charge
Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. It is a conserved property of subatomic particles.
Introduction & History
The study of electric charge began with ancient observations of static electricity. Benjamin Franklin proposed the concepts of positive and negative charge in the 18th century. The electron, the quantum of electric charge, was discovered by J.J. Thomson in 1897.
Key Units
Coulomb (C)
The SI unit of electric charge, equal to the charge of approximately 6.242 × 10¹⁸ electrons.
Elementary charge (e)
The electric charge carried by a single proton or electron, approximately 1.602 × 10⁻¹⁹ C.
Ampere-hour (A·h)
Commonly used in battery capacity, equal to 3,600 coulombs.
Practical Applications
Electronics
Electrochemistry
Particle physics
Electrical engineering
Battery technology
Key Formula
Coulomb's Law
The force (F) between two point charges is directly proportional to the product of the magnitudes of the charges (q₁ and q₂) and inversely proportional to the square of the distance (r) between them, where kₑ is Coulomb's constant.