1. Department of Physics, R.V. College of Engineering, Bangalore 560074, affiliated to Visvesvaraya Technological University, Belagavi 590018, Karnataka, India
2. Department of Physics, Government First Grade College, Srinivasapur 563135, Karnataka, India
3. Department of Physics, Government First Grade College, Devanahalli 562110, Karnataka, India
4. Department of Physics, Government First Grade College, Chikkaballapur 562101, Karnataka, India
5. Department of Physics, Government First Grade College, Mulbagal 563131, Karnataka, India