I am currently studying Practical Electronics for Inventors, Fourth Edition, by Scherz and Monk. Chapter 2.5 Resistance, Resistivity, and Conductivity presents the following image (without description) when discussing the concept of resistance:
I have the following questions:
- What does the \$ A \$ symbol pointing to the left-hand-side of the Ohmic material represent?
- What does the arrow going through the battery symbol represent?
I would appreciate it if people would please take the time to clarify this.