Electric Current, Resistance, and Ohm’s Law
Part 3: Electric Current, Resistance, and Ohm’s Law
In the previous parts, you learned how electric charges create electric fields and store energy. In this part, you will study what happens when charges are allowed to move, producing an electric current. You will learn how voltage drives the motion of charge, how resistance opposes that motion, and how these quantities are related through Ohm’s law, one of the fundamental relationships in circuit analysis.
You will also explore how electrical energy is converted into other forms, such as heat and light, how alternating current powers homes and hospitals, and why electrical safety is especially important in healthcare environments. The part concludes by examining the electrical signals used by the human body, including nerve impulses and the electrical activity of the heart measured with electrocardiograms (ECGs). These topics demonstrate how the same physical principles that govern electrical circuits also underlie many physiological processes and medical technologies.
This part contains the following chapters:
- Introduction to Electric Current, Resistance, and Ohm’s Law
- Current
- Ohm’s Law: Resistance and Simple Circuits
- Resistance and Resistivity
- Electric Power and Energy
- Alternating Current versus Direct Current
- Electric Hazards and the Human Body
- Nerve Conduction–Electrocardiograms
