DataCore interview question

Find largest , second largest element in an array. Find kth largest element in that array? Print all binary strings which doesnt contain consecutive 1, given n which is size of string? Find max value of y-x in an array where x and y is index such that x<y? What is difference between process and thread, what is virtual memory, what is paging? Explain about hash table? What is multi threading and how you can save you critical section code?