Coulomb

Definition

Coulomb is the fundamental unit of electric charge, named after the French physicist Charles-Augustin de Coulomb. It is a measure of the amount of electric charge and is a crucial concept in understanding various topics in electricity and magnetism, such as static electricity, electric fields, electric potential, and the behavior of charged particles.

5 Must Know Facts For Your Next Test

1. One Coulomb is the amount of electric charge carried by a constant current of one ampere flowing for one second.
2. Coulomb's law states that the force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
3. The electric field is a vector field that describes the strength and direction of the electric force experienced by a charged particle at a given point in space.
4. The energy stored in a capacitor is directly proportional to the square of the charge on the capacitor and inversely proportional to the capacitance.
5. The Hall effect is the generation of a potential difference (the Hall voltage) across an electrical conductor transverse to an electric current in the conductor and a magnetic field perpendicular to the current.

Review Questions

• Explain how the concept of Coulomb relates to the topic of static electricity and the conservation of charge.
  • The Coulomb is the fundamental unit of electric charge, which is the property that gives rise to static electricity. According to the principle of conservation of charge, the total electric charge in an isolated system is constant and cannot be created or destroyed, only transferred or transformed. This means that the total charge, measured in Coulombs, must be conserved in any static electricity scenario, such as the buildup of charge on an object or the transfer of charge between objects.
• Describe how Coulomb's law relates to the concept of an electric field and the behavior of electric field lines.
  • Coulomb's law, which states that the force between two charges is inversely proportional to the square of the distance between them, is the foundation for understanding electric fields. The electric field is defined as the force per unit charge exerted on a test charge, and it can be visualized using electric field lines. The direction and strength of the electric field at any point is determined by the distribution and magnitude of the charges, as described by Coulomb's law. The pattern of electric field lines around multiple charges is a direct consequence of the vectorial nature of the electric fields produced by each individual charge, as per Coulomb's law.
• Analyze how the concept of Coulomb is related to the energy stored in a capacitor and the phenomenon of the Hall effect.
  • The energy stored in a capacitor is directly proportional to the square of the charge on the capacitor, as measured in Coulombs. This relationship arises from the work done in moving charges against the electric field within the capacitor. Furthermore, the Hall effect, which is the generation of a potential difference across an electrical conductor due to a magnetic field and an electric current, is fundamentally dependent on the motion of charged particles, or Coulombs, within the conductor. The Hall voltage generated is proportional to the strength of the magnetic field, the current, and the nature of the charge carriers, all of which are characterized in terms of Coulombs.

Related terms

Electric Charge: The fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. Electric charge can be positive or negative.

Coulomb's Law: The law that describes the force between two stationary, electrically charged objects, stating that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

Electric Field: The region surrounding a charged object in which other charged objects experience a force. The electric field is defined as the force per unit charge exerted on a test charge.