are header files also get converted into binary code during compilation
About header files
Yes, Header file resolution is done by pre-processor not by compiler. So all the function that you are using in your program (defined in the header file) are referenced by pre-processor and after it will be normal function and everything will be converted into binary file during compilation.
What is the meaning of refrenced here
The code for each function is written in the header file that you are including. During referencing each function is replaced by its actual code.
In video it is mentioned that 1st bit of memory represent whether the no is positive or -ve so if i have a no with all bits 1 in integer memory and its a positive no so its not hold true where i am wrong
please share the link of video.
Its clear now but i have a doubt - what will be the output if i store -ve value in unsigned integer
The negative value will be treated as positive integers. ie in the binary representation the msb bit treated as the signed bit in signed integer representation. So while you are storing the negative value in unsigned integer its msb will be one it will be treated as normal positive integer. eg if you are storing -5 then its equivalent (2^32-5+1) will be strored.