1. What is the type of the algorithm used in solving the 8 Queens problem?
Ans: Backtracking

2. What is the difference between a Stack and an Array?
Ans:
Stack
i) Stack is an ordered collection of items
ii) Stack is a dynamic object whose size is constantly changing as items are pushed and popped.
iii) Stack may contain different data types
iv) Stack is declared as a structure containing an array to hold the element of the stack, and an integer to indicate the current stack top within the array.
Array
i) Array is an ordered collection of items
ii) Array is a static object i.e. no of item is fixed and is assigned by the declaration of the array
iii) It contains same data types.
iv) Array can be home of a stack i.e. array can be declared large enough for maximum size of the stack.

3. What is sequential search?
Ans: In sequential search each item in the array is compared with the item being searched until a match occurs. It is applicable to a table organized either as an array or as a linked list.

4. What actions are performed when a function returns?
Ans:
i) Return address is retrieved
ii) Function’s data area is freed
iii) Branch is taken to the return address

5. Is it necessary to sort a file before searching a particular item?
Ans:
If less work is involved in searching an element than to sort and then extract, then we don’t go for sort
If frequent use of the file is required for the purpose of retrieving specific element, it is more efficient to sort the file.
Thus it depends on situation.

6. What are the advantages of linked list over array (static data structure)?
Ans: 
The disadvantages of array are
i) unlike linked list it is expensive to insert and delete elements in the array
ii) One can’t double or triple the size of array as it occupies block of memory space.

In linked list
i) each element in list contains a field, called a link or pointer which contains the address of the next element
ii) Successive element’s need not occupy adjacent space in memory.

7. Can we apply binary search algorithm to a sorted linked list, why?
Ans: No we cannot apply binary search algorithm to a sorted linked list, since there is no way of indexing the middle element in the list. This is the drawback in using linked list as a data structure.

8. What do you mean by recursive definition?
Ans: The definition which defines an object in terms of simpler cases of itself is called recursive definition.

9. What do you mean by garbage collection?
Ans: It is a technique in which the operating system periodically collects all the deleted space onto the free storage list.
It takes place when there is minimum amount of space left in storage list or when CPU is ideal.
The alternate method to this is to immediately reinsert the space into free storage list which is time consuming.

10. What are the disadvantages array implementations of linked list?
Ans:
i) The no of nodes needed can’t be predicted when the program is written.
ii) The no of nodes declared must remain allocated throughout its execution