After passing his FA examinations in 1908, Mitra was admitted as a student in Presidency College of the University of Calcutta where he earned a B.Sc. He continued to develop a passion for physics and scientific research, and was accepted by Jagadish Bose as a research scholar upon completing his master's degree in 1912 with the highest honours. He worked under Professor Bose for a few months before being forced to end his studies due to his family's financial difficulties.