[1] Born in village Rohana Kalan of the Muzaffarnagar district of the Indian state Uttar Pradesh, Tyagi received his MSc degree in physics from University of Lucknow, India.

During his doctorate studies at RWTH, he was employed as a laboratory development engineer by Telefunken AG, Ulm, Germany, from 1962 to 1964.

Since February 1980, he has been a visiting professor in the Department of Electrical Engineering ESAT Laboratory, Katholieke Universiteit Leuven, on leave of absence from IITK.

In July 2003, he joined the electronics and communications engineering department of Jaypee Institute of Information Technology, Noida.

Tyagi contributed the first chapter in Metal-semiconductor Schottky barrier junctions and their applications, Plenum Press New York 1984.