One of the strongest points of this book is its exhaustive coverage of topics as per almost all Indian state and central university syllabi (e.g., VTU, JNTU, Anna University, RGPV, AKTU). The PDF typically includes:
Verdict: The book follows a traditional, bottom-up approach. If you need a reference for a standard "Signals & Systems" syllabus, this PDF covers everything. Signals And Systems By Anand Kumar.pdf
Chapter 4 (Convolution) is usually the first "filter" that fails students. One of the strongest points of this book
A major advantage of a PDF over a physical book is text search. When you get stuck on a problem type (e.g., "Find the Nyquist rate for ( \textsinc^2(100t) )"), use CTRL+F and search the exact term. Kumar usually clusters similar problems together. Verdict: The book follows a traditional, bottom-up approach