there is no use for iostream.h because it is obsolete. use iostream instead (without the .h extension) assuming your compiler supports it. Old compilers such as original Turbo C++ may recognaize iostream.h.
It defines the c++ iostream classes -- output text to the console monitor.
>in which header file the operators will be stored in c++
It could be a trick question... perhaps the question is asking about the normal C++ operators such as +,-, etc.. In that case, there is no header file as these are built into the C++ language.