1. Department of Physics, Ewing Christian College, University of Allahabad, Prayagraj-211003,
India
2. Department of Physics, Deen Dayal Upadhyay Govt. P.G. College, Saidabad, Prayagraj-
221508, India
3. Department of Physics, Chaudhary Mahadeo Prasad Degree College, University of Allahabad,
Prayagraj- 211002, India.
4. Department of Physics & Electronics, Dr. Ram Manohar Lohia Avadh University, Ayodhya-224
001, India