Many websites promising a "Google Drive download link" are traps. They may:
Many engineering colleges in India have partnerships with NPTEL, DELNET, or S. Chand’s institutional access. Check if your college provides a free digital membership.
Yes, but only under specific conditions:
Buy a used physical copy (₹100–₹200) – you may get a scratch code for an e-book. Some sellers include original PDFs with purchase.