Definitions⌗

  • (A) ampere or amp (p6)
    • Unit of current
    • Interchangeable unit for 1 C/s
  • (C) coulomb (p6)
    • Unit of electrical charge
  • Voltage
    • potential difference or just potential (NOT potential energy)
  • (V) volt (p14)
    • Unit of measure of Voltage
    • 1 volt = 1 joule / 1 coulomb
  • Power (p14)
    • power = dW/dt

Chapter 2: Theory⌗

Voltage⌗

To get a mental image of how a battery generates an EMF through a circuit, we envision that chemical reactions inside yield free electrons that quickly build in number within the negative terminal region (anode material), causing an electron concentration. This concentration is full of repulsive force (electrons repel) that can be viewed as a kind of “electrical pressure”

With a load (e.g., flashlight lamp, …) placed between the battery’s terminals, electrons from the battery’s negative terminal attempt to alleviate this pressure by dispersing into the circuit. These electrons increase the concentration of free electrons within the end of the conductor attached to the negative terminal. Even a small percentage difference in free electron concentration in one region gives rise to great repulsive forces between free electrons. (p11) 2.3.1 The Mechanisms of Voltage