Voltage
**Fundamentals of Voltage:**
Voltage is the measure of electric potential energy per unit charge in a system. It is denoted by ΔV and is represented in joules per coulomb. The volt, named after Alessandro Volta, is the unit for electric potential, voltage, and electromotive force. It determines the direction in which negatively charged objects are attracted towards higher voltages, with the electrochemical potential being directly measurable.
**Electrodynamics and Voltage:**
In electrodynamics, the concept of electric potential extends beyond a simple electric field relationship. Some define voltage as the line integral of the electric field, leading to potential not being uniquely determined up to a constant. The voltage between two points in a system can vary based on the path taken, requiring a broader understanding of its calculation and implications.
**Circuit Theory and Voltage:**
Circuit analysis involves using lumped element models to represent and analyze circuits, with well-defined voltages between nodes. Magnetic fields in circuits are contained within individual elements, and the addition of mutual inductance elements can model their effects. Accurate voltage measurements are crucial in circuit analysis, requiring specific measurement points and instruments tailored for different purposes.