Q1. Graph is a:

A) Linear data structure
B) Non-linear data structure
C) Sequential structure
D) Static array

Answer: B

Explanation: Graph is a non-linear data structure consisting of vertices (nodes) and edges (connections).

Q2. The points in a graph are called:

A) Edges
B) Vertices
C) Paths
D) Trees

Answer: B

Explanation: Vertices or nodes are the main elements of a graph.

Q3. The connection between two vertices is called:

A) Node
B) Edge
C) Root
D) Branch

Answer: B

Explanation: An edge represents a connection between two vertices.

Q4. A graph with direction on edges is called:

A) Undirected Graph
B) Directed Graph
C) Weighted Graph
D) Cyclic Graph

Answer: B

Explanation: Directed graph (Digraph) contains edges with a specific direction.

Q5. A graph without direction on edges is called:

A) Directed Graph
B) Weighted Graph
C) Undirected Graph
D) Tree

Answer: C

Explanation: In an undirected graph, edges have no direction.

Q6. Graph traversal means:

A) Sorting vertices
B) Visiting all vertices systematically
C) Deleting edges
D) Adding nodes only

Answer: B

Explanation: Traversal means visiting each vertex of the graph in a proper order.

Q7. BFS stands for:

A) Binary First Search
B) Breadth First Search
C) Branch First Search
D) Balanced First Search

Answer: B

Explanation: BFS explores graph nodes level by level.

Q8. DFS stands for:

A) Depth First Search
B) Data First Search
C) Direct First Search
D) Double First Search

Answer: A

Explanation: DFS explores as deep as possible before backtracking.

Q9. BFS mainly uses:

A) Stack
B) Queue
C) Tree
D) Heap

Answer: B

Explanation: BFS uses a queue to process nodes in level order.

Q10. DFS mainly uses:

A) Queue
B) Stack
C) Array
D) Linked List only

Answer: B

Explanation: DFS uses stack or recursion internally.

Q11. Adjacency Matrix is used for:

A) Stack representation
B) Graph representation
C) Queue implementation
D) Tree balancing

Answer: B

Explanation: Adjacency Matrix is a common method to represent graphs.

Q12. Adjacency List is better when graph is:

A) Dense
B) Sparse
C) Full
D) Balanced

Answer: B

Explanation: Adjacency List saves memory when the graph has fewer edges.

Q13. A graph with no cycles is called:

A) Cyclic Graph
B) Acyclic Graph
C) Weighted Graph
D) Directed Graph

Answer: B

Explanation: A graph without any cycle is called an acyclic graph.

Q14. A tree is a special type of:

A) Queue
B) Graph
C) Stack
D) Array

Answer: B

Explanation: Tree is a connected acyclic graph.

Q15. Number of edges connected to a vertex is called:

A) Height
B) Degree
C) Weight
D) Path

Answer: B

Explanation: Degree of a vertex is the number of edges incident to it.

Q16. In directed graph, incoming edges are called:

A) Out-degree
B) In-degree
C) Total degree
D) Cycle degree

Answer: B

Explanation: In-degree means the number of edges coming into a vertex.

Q17. In directed graph, outgoing edges are called:

A) In-degree
B) Out-degree
C) Total degree
D) Loop degree

Answer: B

Explanation: Out-degree means the number of edges going out from a vertex.

Q18. A graph with values on edges is called:

A) Simple graph
B) Weighted graph
C) Circular graph
D) Directed graph

Answer: B

Explanation: Weighted graph stores values like cost, distance, or time on edges.

Q19. A path that starts and ends at same vertex is called:

A) Tree
B) Cycle
C) Chain
D) Queue

Answer: B

Explanation: A cycle is a closed path in a graph.

Q20. Which traversal is used for shortest path in unweighted graph?

A) DFS
B) BFS
C) Tree traversal
D) Hashing

Answer: B

Explanation: BFS finds the shortest path in unweighted graphs.

Q21. Which graph has every vertex connected to every other vertex?

A) Null graph
B) Complete graph
C) Sparse graph
D) Tree

Answer: B

Explanation: In a complete graph, every pair of vertices has an edge.

Q22. Graph with no edges is called:

A) Complete graph
B) Null graph
C) Directed graph
D) Weighted graph

Answer: B

Explanation: Null graph contains only vertices and no edges.

Q23. Self-loop means:

A) Edge connecting two different vertices
B) Edge connecting a vertex to itself
C) Multiple edges
D) No edge

Answer: B

Explanation: A self-loop starts and ends at the same vertex.

Q24. Multiple edges between same vertices form:

A) Simple graph
B) Multigraph
C) Tree
D) Null graph

Answer: B

Explanation: Multigraph allows more than one edge between the same pair of vertices.

Q25. Which algorithm uses recursion naturally?

A) BFS
B) DFS
C) Queue
D) Hashing

Answer: B

Explanation: DFS is naturally implemented using recursion.

Q26. The sum of degrees of all vertices equals:

A) Number of vertices
B) Twice the number of edges
C) Number of paths
D) Number of trees

Answer: B

Explanation: In graph theory, sum of degrees = 2 × number of edges.

Q27. Which representation uses more memory for sparse graph?

A) Adjacency List
B) Adjacency Matrix
C) Linked List
D) Queue

Answer: B

Explanation: Adjacency Matrix wastes memory in sparse graphs.

Q28. Graph traversal starts from:

A) Root node only
B) Any selected vertex
C) Last vertex only
D) Edge only

Answer: B

Explanation: Traversal can start from any chosen vertex.

Q29. Minimum number of edges in a tree with n vertices is:

A) n
B) n − 1
C) n + 1
D) 2n

Answer: B

Explanation: A tree with n vertices always has exactly n − 1 edges.

Q30. Which structure is best for social network modeling?

A) Stack
B) Queue
C) Graph
D) Array

Answer: C

Explanation: Social networks are naturally represented using graph structures.