Department of physics in TNB College was establish in 1916 under the founder Prof. P.B. Gupta. Some the Renowned teachers and head of the department are Prof. S.K. Mitra, who become first director of National Physical Laboratory (N.P.L), New Delhi. Late Dr. Sudharshan Pd. Sinha, who was the former principal of T.N.B college for more than 14 years was the eminent scientist in the field of spectro copy. Some Renowned teachers of department are Prof. N.R. Mitra, Prof. R.P. Thakur, Prof. R.N. Singh, Prof. P.S. Mishra and many more P.G. teaching was started here for the Bhagalpur University in 1967.