Orthogonal matrices satisfying Q^TQ = I — IITM BS previous year questions

Orthogonal matrices satisfying Q^TQ = I is part of Orthogonal Transformations and Rotations, Week 8 in Mathematics 2. Prasnya files every IIT Madras BS previous year question from this subtopic here, each one with a worked explanation. Take the whole set as a timed mock and you get accuracy, pacing and per-question analysis back.