00336nam a2200121Ia 4500008004100000100006200041245001400103260005100117300000900168650001200177942000800189999001700197190216s9999||||xx |||||||||||||| ||und||  a"Choudhury Rs, Ramakrishnan T V, Subramanyam Etc........" 0aClass Xii  bNational Council Of Educational Researchc1990  a136p  aPhysics  cREF  c36103d36103