Electrician's Licensing Practice Exam

Which terminal of a battery is characterized by a surplus of protons?

1. Negative terminal

2. Positive terminal

3. Both terminals

4. Neither terminal

The correct answer is: Positive terminal

The positive terminal of a battery is characterized by a surplus of protons. In a battery, the positive terminal (also known as the cathode) is the site where reduction occurs, meaning that it attracts electrons from the external circuit. As electrons flow towards the positive terminal, it creates a surplus of protons in the electrolyte that surround it. This surplus of charge at the positive terminal makes it positively charged relative to the negative terminal (anode), which has a deficit of protons and is where oxidation occurs. Understanding this concept is pivotal in grasping how batteries function. The movement of electrons is essential to the flow of electrical current, and the arrangement of protons at the terminals plays a direct role in establishing the electric potential difference that drives this current.