Which chapters in the NEC® apply generally unless modified by later chapters?

The chapters in the National Electrical Code (NEC®) that apply generally unless modified by later chapters are indeed the first four chapters. Chapters 1 through 4 provide foundational information that establishes general wiring and installation requirements applicable to the entire code. These chapters encompass vital topics such as definitions, general requirements for electrical installations, allowable methods, and other essential guidelines that are pertinent across various electrical applications.

Chapter 1 introduces the code's scope, purpose, and general requirements. Chapter 2 reviews the wiring methods and materials, while Chapter 3 concerns itself with the installation requirements for specific types of conductors and raceways. Chapter 4 covers special occupancy installations and the requirements peculiar to those situations. Since these chapters set the general framework for understanding how the NEC is to be applied, they ensure that the fundamental principles are adhered to before any specialized modifications are introduced in subsequent chapters.

Other options don't accurately represent the scope and application of the NEC. For example, the chapters beyond four delve into specific types of installations or unique situations that may not apply in all scenarios, hence they do not establish the general applicability as strongly as the first four chapters.