00322nam a2200133Ia 4500008004100000082000800041082001000049100001900059100001800078245001200096260001300108260005800121260000900179230118s9999||||xx |||||||||||||| ||und||  a530  bKUM/P  aaravindbkumar  ba.nmaheshwari 0aphysics  anewdelhi  bnational council of educational research and training  c1989