Here is the reality: Unlike textbooks by authors like Sedra/Smith or Rashid, a verified solution manual for Dubey is extremely rare (often only available to instructors). But that does not mean you are stuck.
Typical Problem (Chapter 4 – DC Drives): A separately excited DC motor is fed from a single-phase fully controlled converter. Calculate the speed for a given firing angle.
Since a verified solutions PDF does not legally exist in the public domain, use these alternatives to build your own answer key:
Power Semiconductor Controlled Drives by G.K. Dubey overlaps significantly. Some problems are solved in that text.
Many IIT professors base their problem-solving sessions directly on Dubey. Search YouTube for "NPTEL Electrical Drives solved problems."
