# Data Structure MCQ with Answers

**Data Structure MCQ with Answers:** Here are multiple-choice questions (MCQs) on data structures along with concise descriptions and answers. Test your knowledge on various data structures such as heaps, binary search trees, stacks, queues, hash tables, and more.

## Data Structure MCQ with Answers

**Multiple Choice Questions and Correct Answers:-**

1. Which if the following is/are the levels of implementation of data structure

A) Abstract level

B) Application level

C) Implementation level

D) All of the above

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Correct Answers : D

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2. A binary search tree whose left subtree and right subtree differ in hight by at most 1 unit is called ……

A) AVL tree

B) Red-black tree

C) Lemma tree

D) None of the above

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Correct Answers 😀

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3. ……………….. level is where the model becomes compatible executable code

A) Abstract level

B) Application level

C) Implementation level

D) All of the above

Correct Answers :C

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4. Stack is also called as

A) Last in first out

B) First in last out

C) Last in last out

D) First in first out

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Correct Answers :A

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5. Which of the following is true about the characteristics of abstract data types?

i) It exports a type.

ii) It exports a set of operations

A) True, False

B) False, True

C) True, True

D) False, False

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Correct Answers :C

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6. …………… is not the component of data structure.

A) Operations

B) Storage Structures

C) Algorithms

D) None of above

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Correct Answers 😀

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7. Which of the following is not the part of ADT description?

A) Data

B) Operations

C) Both of the above

D) None of the above

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Correct Answers 😀

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8. Inserting an item into the stack when stack is not full is called ………….

Operation and deletion of item form the stack, when stack is not empty is called ………..operation.

A) push, popB) pop, push

C) insert, delete

D) delete, insert

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Correct Answers :A

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9. ……………. Is a pile in which items are added at one end and removed from the other.

A) Stack

B) Queue

C) List

D) None of the above

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Correct Answers :B

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10. ………… is very useful in situation when data have to stored and then retrieved in reverse order.

A) Stack

B) Queue

C) List

D) Link list

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Correct Answers :A

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11. Which data structure allows deleting data elements from and inserting at rear?

A) Stacks

B) Queues

C) Dequeues

D) Binary search tree

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Correct Answers :B

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12. Which of the following data structure can’t store the non-homogeneous data elements?

A) Arrays

B) Records

C) Pointers

D) Stacks

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Correct Answers :A

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13. A ……. is a data structure that organizes data similar to a line in the supermarket, where the first one in line is the first one out.

A) Queue linked list

B) Stacks linked list

C) Both of them

D) Neither of them

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Correct Answers :A

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14. Which of the following is non-liner data structure?

A) Stacks

B) List

C) Strings

D) Trees

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Correct Answers 😀

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15. Herder node is used as sentinel in …..

A) Graphs

B) Stacks

C) Binary tree

D) Queues

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Correct Answers :C

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16. Which data structure is used in breadth first search of a graph to hold nodes?

A) Stack

B) queue

C) Tree

D) Array

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Correct Answers :B

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17. Identify the data structure which allows deletions at both ends of the list but insertion at only one end.

A) Input restricted dequeue

B) Output restricted qequeue

C) Priority queues

D) Stack

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Correct Answers :A

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18. Which of the following data structure is non linear type?

A) Strings

B) Lists

C) Stacks

D) Graph

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Correct Answers 😀

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19. Which of the following data structure is linear type?

A) Graph

B) Trees

C) Binary tree

D) Stack

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Correct Answers 😀

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20. To represent hierarchical relationship between elements, Which data structure is suitable?

A) Dequeue

B) Priority

C) Tree

D) Graph

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Correct Answers :C

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21. A directed graph is ………………. if there is a path from each vertex to every other vertex in the digraph.

A) Weakly connected

B) Strongly Connected

C) Tightly Connected

D) Linearly Connected

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Correct Answers :B

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22. In the …………….. traversal we process all of a vertex’s descendants before we move to an adjacent vertex.

A) Depth First

B) Breadth First

C) With First

D) Depth Limited

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Correct Answers :A

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23. State True of False.

i) Network is a graph that has weights or costs associated with it.

ii) An undirected graph which contains no cycles is called a forest.

iii) A graph is said to be complete if there is no edge between every pair of vertices.

A) True, False, True

B) True, True, False

C) True, True, True

D) False, True, True

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Correct Answers :B

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24. Match the following.

a) Completeness i) How long does it take to find a solution

b) Time Complexity ii) How much memory need to perform the search.

c) Space Complexity iii) Is the strategy guaranteed to find the solution when there in one.

A) a-iii, b-ii, c-i

B) a-i, b-ii, c-iii

C) a-iii, b-i, c-ii

D) a-i, b-iii, c-ii

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Correct Answers :C

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25. The number of comparisons done by sequential search is ………………

A) (N/2)+1

B) (N+1)/2

C) (N-1)/2

D) (N+2)/2

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Correct Answers :B

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26. In ……………, search start at the beginning of the list and check every element in the list.

A) Linear search

B) Binary search

C) Hash Search

D) Binary Tree search

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Correct Answers :A

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27. State True or False.

i) Binary search is used for searching in a sorted array.

ii) The time complexity of binary search is O(logn).

A) True, False

B) False, True

C) False, False

D) True, True

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Correct Answers 😀

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28. Which of the following is not the internal sort?

A) Insertion Sort

B) Bubble Sort

C) Merge Sort

D) Heap Sort

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Correct Answers :C

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29. State True or False.

i) An undirected graph which contains no cycles is called forest.

ii) A graph is said to be complete if there is an edge between every pair of vertices.

A) True, True

B) False, True

C) False, False

D) True, False

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Correct Answers :A

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30. A graph is said to be ……………… if the vertices can be split into two sets V1 and V2 such there are no edges between two vertices of V1 or two vertices of V2.

A) Partite

B) Bipartite

C) Rooted

D) Bisects

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Correct Answers :B

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31. In a queue, the initial values of front pointer f rare pointer r should be …….. and ……….. respectively.

A) 0 and 1

B) 0 and -1

C) -1 and 0

D) 1 and 0

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Correct Answers :B

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32. In a circular queue the value of r will be ..

A) r=r+1

B) r=(r+1)% [QUEUE_SIZE – 1]

C) r=(r+1)% QUEUE_SIZE

D) r=(r-1)% QUEUE_SIZE

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Correct Answers :C

33. Which of the following statement is true?

i) Using singly linked lists and circular list, it is not possible to traverse the list backwards.

ii) To find the predecessor, it is required to traverse the list from the first node in case of singly linked list.

A) i-only

B) ii-only

C) Both i and ii

D) None of both

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Correct Answers :C

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34. The advantage of …………….. is that they solve the problem if sequential storage representation. But disadvantage in that is they are sequential lists.

A) Lists

B) Linked Lists

C) Trees

D) Queues

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Correct Answers :B

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35. What will be the value of top, if there is a size of stack STACK_SIZE is 5

A) 5

B) 6

C) 4

D) None

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Correct Answers :C

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36. ………… is not the operation that can be performed on queue.

A) Insertion

B) Deletion

C) Retrieval

D) Traversal

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Correct Answers 😀

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37. There is an extra element at the head of the list called a ……….

A) Antinel

B) Sentinel

C) List header

D) List head

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Correct Answers :B

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38. A graph is a collection of nodes, called ………. And line segments called arcs or ……….. that connect pair of nodes.

A) vertices, edges

B) edges, vertices

C) vertices, paths

D) graph node, edges

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Correct Answers :A

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39. A ……….. is a graph that has weights of costs associated with its edges.

A) Network

B) Weighted graph

C) Both A and B

D) None A and B

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Correct Answers :C

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40. In general, the binary search method needs no more than ……………. comparisons.

A) [log2n]-1

B) [logn]+1

C) [log2n]

D) [log2n]+1

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Correct Answers 😀

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41. Which of the following is not the type of queue?

A) Ordinary queue

B) Single ended queue

C) Circular queue

D) Priority queue

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Correct Answers :B

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42. The property of binary tree is

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A) The first subset is called left subtree

B) The second subtree is called right subtree

C) The root cannot contain NULL

D) The right subtree can be empty

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Correct Answers 😀

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43. State true or false.

i) The degree of root node is always zero.

ii) Nodes that are not root and not leaf are called as internal nodes.

A) True, True

B) True, False

C) False, True

D) False, False

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Correct Answers :C

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44. Any node is the path from the root to the node is called

A) Successor node

B) Ancestor node

C) Internal node

D) None of the above

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Correct Answers :B

45. State true of false.

i) A node is a parent if it has successor nodes.

ii) A node is child node if out degree is one.

A) True, True

B) True, False

C) False, True

D) False, False

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Correct Answers :B

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46. ………………. is not an operation performed on linear list

a) Insertion b) Deletion c) Retrieval d) Traversal

A) only a,b and c

B) only a and b

C) All of the above

D) None of the above

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Correct Answers 😀

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47. Which is/are the application(s) of stack

A) Function calls

B) Large number Arithmetic

C) Evaluation of arithmetic expressions

D) All of the above

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Correct Answers 😀

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48. A …………… is an acyclic digraph, which has only one node with indegree 0, and other nodes have in-degree 1.

A) Directed tree

B) Undirected tree

C) Dis-joint tree

D) Direction oriented tree

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Correct Answers :A

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49. …………………. Is a directed tree in which outdegree of each node is less than or equal to two.

A) Unary tree

B) Binary tree

C) Trinary tree

D) Both B and C

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Correct Answers :B

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50. State true or false.

i) An empty tree is also a binary tree.

ii) In strictly binary tree, the out-degree of every node is either o or 2.

A) True, False

B) False, True

C) True, True

D) False, False

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Correct Answers :C

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51. Which of the following data structures are indexed structures?

A. Linear arrays

B. Linked lists

C. Queue

D. Stack

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Correct Answers :A

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52. Which of the following data structure store the homogeneous data elements?

A. Arrays

B. Records

C. Pointers

D. Lists

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Correct Answers :B

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53. When new data are to be inserted into a data structure, but there is not available space; this situation is usually called ….

A. Underflow

B. overflow

C. houseful

D. saturated

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Correct Answers :B

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54. A data structure where elements can be added or removed at either end but not in the middle is called …

A. linked lists

B. stacks

C. queues

D. dequeue

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Correct Answers 😀

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55. Operations on a data structure may be …..

A. creation

B. destruction

C. selection

D. all of the above

Correct Answers 😀

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56. The way in which the data item or items are logically related defines …..

A. storage structure

B. data structure

C. data relationship

D. data operation

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Correct Answers :B

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57. Which of the following are the operations applicable an primitive data structures?

A. create

B. destroy

C. update

D. all of the above

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Correct Answers 😀

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58. The use of pointers to refer elements of a data structure in which elements are logically adjacent is ….

A. pointers

B. linked allocation

C. stack

D. queue

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Correct Answers :B

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59. Arrays are best data structures

A. for relatively permanent collections of data

B. for the size of the structure and the data in the structure are constantly changing

C. for both of above situation

D. for non of above situation

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Correct Answers :C

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60. Which of the following statement is false?

A. Arrays are dense lists and static data structure.

B. Data elements in linked list need not be stored in adjacent space in memory

C. Pointers store the next data element of a list

D. Linked lists are collection of the nodes that contain information part and next pointer.

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Correct Answers :C

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61. Which of the following data structure is non-linear type?

A) Strings

B) Lists

C) Stacks

D) Tree

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Correct Answers 😀

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62. Which of the following data structure is linear type?

A) Array

B) Tree

C) Graphs

D) Hierarchy

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Correct Answers :A

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63. The logical or mathematical model of a particular organization of data is called a ………

A) Data structure

B) Data arrangement

C) Data configuration

D) Data formation

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Correct Answers :A

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64. The simplest type of data structure is ………………

A) Multidimensional array

B) Linear array

C) Two dimensional array

D) Three dimensional array

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Correct Answers :B

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65. Linear arrays are also called ……………….

A) Straight line array

B) One-dimensional array

C) Vertical array

D) Horizontal array

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Correct Answers :B

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66. Arrays are best data structures …………

A) For relatively permanent collections of data

B) For the size of the structure and the data in the structure are constantly changing

C) For both of above situation

D) For none of the above

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Correct Answers :A

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67. Which of the following data structures are indexed structures?

A) Linear arrays

B) Linked lists

C) Graphs

D) Trees

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Correct Answers :A

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68. Each node in a linked list has two pairs of ………….. and ……………….

A) Link field and information field

B) Link field and avail field

C) Avail field and information field

D) Address field and link field

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Correct Answers :A

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69. A …………………… does not keep track of address of every element in the list.

A) Stack

B) String

C) Linear array

D) Queue

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Correct Answers :C

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70. When does top value of the stack changes?

A) Before deletion

B) While checking underflow

C) At the time of deletion

D) After deletion

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Correct Answers 😀

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71. Which of the following data structure is non-linear type?

A) Strings

B) Lists

C) Stacks

D) Tree

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Correct Answers 😀

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72. Which of the following data structure is linear type?

A) Array

B) Tree

C) Graphs

D) Hierarchy

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Correct Answers :A

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73. The logical or mathematical model of a particular organization of data is called a ………

A) Data structure

B) Data arrangement

C) Data configuration

D) Data formation

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Correct Answers :A

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74. The simplest type of data structure is ………………

A) Multidimensional array

B) Linear array

C) Two dimensional array

D) Three dimensional array

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Correct Answers :B

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75. Linear arrays are also called ……………….

A) Straight line array

B) One-dimensional array

C) Vertical array

D) Horizontal array

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Correct Answers :B

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76. Arrays are best data structures …………

A) For relatively permanent collections of data.

B) For the size of the structure and the data in the structure are constantly changing

C) For both of above situation

D) For none of the above

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Correct Answers :A

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77. Which of the following data structures are indexed structures?

A) Linear arrays

B) Linked lists

C) Graphs

D) Trees

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Correct Answers :A

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78. Each node in a linked list has two pairs of ………….. and ……………….

A) Link field and information field

B) Link field and avail field

C) Avail field and information field

D) Address field and link field

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Correct Answers :A

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79. A …………………… does not keep track of address of every element in the list.

A) Stack

B) String

C) Linear array

D) Queue

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Correct Answers :C

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80. When does top value of the stack changes?

A) Before deletion

B) While checking underflow

C) At the time of deletion

D) After deletion

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Correct Answers 😀

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91. Arrays are best data structures

A) for relatively permanent collections of data

B) for the size of the structure and the data in the structure are constantly changing

C) for both of above situation

D) for none of above situation

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Correct Answers :A

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92. Which of the following data structure is not linear data structure?

A) Arrays

B) Linked lists

C) Both of the above

D) None of the above

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Correct Answers 😀

93. The disadvantage in using a circular linked list is …………………….

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A) It is possible to get into infinite loop.

B) Last node points to first node.

C) Time consuming

D) Requires more memory space

Correct Answers :A

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94. A linear list in which each node has pointers to point to the predecessor and successors nodes is called as ..

A) Singly Linked List

B) Circular Linked List

C) Doubly Linked List

D) Linear Linked List

Correct Answers :C

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95. A ……………….. is a linear list in which insertions and deletions are made to from either end of the structure.

A) circular queue

B) random of queue

C) priority

D) dequeue

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Correct Answers : D

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96. In a priority queue, insertion and deletion takes place at ………………

A) front, rear end

B) only at rear end

C) only at front end

D) any position

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Correct Answers : D

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97. The time complexity of quick sort is …………..

A) O(n)

B) O(n2)

C) O(n log n)

D) O(log n)

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Correct Answers : C.

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98. Which of the following is an application of stack?

A) finding factorial

B) tower of Hanoi

C) infix to postfix conversion

D) all of the above

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Correct Answers : B.

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99. The data structure which is one ended is ………………

A) queue

B) stack

C) tree

D) graph

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Correct Answers :B.

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100. A list which displays the relationship of adjacency between elements is said to be

A) linear

B) non linear

C) linked list

D) trees

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Correct Answers : A.