A joint initiative of IITs and IISc, the NPTEL GATE Portal provides free video solutions and practice sets specifically for engineering students.

You don't always need to buy expensive books to get quality solutions. Several reputable platforms provide past papers (often from 1990 to the most recent 2025/2026 sessions) for free:

Sites like Testbook and Physics Wallah offer downloadable PDFs with detailed step-by-step solutions for at least the last 5–10 years.

Unitoperation is a dedicated hub for Chemical Engineering that houses a massive collection of solved questions, though some advanced features may require a subscription. Why Solved Papers are Critical GATE 2026 Test PAPERS & Syllabus - IIT Guwahati

For anyone tackling , solved papers are arguably your most potent study tool. They aren't just for practice—they’re a "cheat sheet" for understanding how the examiners think. Where to Find Free Solved Papers

The conducting IIT (such as IIT Guwahati for GATE 2026) typically hosts official question papers and answer keys for recent years.