1. Department of Physics, BMS Institute of Technology and Management, Bangalore 560064, Affiliated to Visvesveraya Technological University, Belagavi 590018, Karnataka, India
2. Department of Physics, Government First Grade College, Devanahalli 562110, Karnataka, India
3. Department of Physics, Government First Grade College, Chikkaballapur 562101, Karnataka, India
4. Department of Physics, Government First Grade College, Kolar 563101, Karnataka, India