C Interview questions

What is your core experience in working with the C language and where have you used it?
If I wanted to sort data, what is the quickest way of doing so in C?
What is the significance of a null pointer in C?
What are executable files and how do you reduce its file size?
What are bitwise operator and which ones are used to turn off or put a particular bit in a number?
If I ask how much portion of memory is allocated, where will you look at to determine so?
Explain the difference in terms of usage between a memory copy and a string copy?
If my program exits the main function but I still need to execute a code will I be able to do so?
What expertise would you be brining in to our organization with your domain knowledge?
How far along do you plan to go if given an opportunity in our company?