Affiliation: | (1) Department of Physics, Farook College, Calicut, 673 632, India;(2) Kingstree Sr. High, 616 Martin Luther King Avenue, Kingstree, South Carolina, USA;(3) Department of Physics, M.E.S. College, Ponnani, 679 586, India;(4) Department of Physics, University of Calicut, Calicut, 673 635, India |