# Recent questions and answers in Graph Theory

1
How many undirected graphs (not necessarily connected) can be constructed out of a given set $V=\{v_1, v_2, \dots v_n\}$ of $n$ vertices? $\frac{n(n-1)} {2}$ $2^n$ $n!$ $2^\frac{n(n-1)} {2}$
1 vote
2
Let $G$ be a simple undirected graph on $n=3x$ vertices $(x \geq 1)$ with chromatic number $3$, then maximum number of edges in $G$ is $n(n-1)/2$ $n^{n-2}$ $nx$ $n$
3
A simple graph is one in which there are no self loops and each pair of distinct vertices is connected by at most one edge. Let G be a simple graph on 8 vertices such that there is a vertex of degree 1, a vertex of degree 2, a vertex of degree 3, a vertex of degree 4, a vertex of ... 6 and a vertex of degree 7. Which of the following can be the degree of the last vertex? (A) 3 (B) 0 (C) 5 (D) 4
4
5
6
1 vote
7
Consider a graph $G$ with $2^{n}$ vertices where the level of each vertex is a $n$ bit binary string represented as $a_{0},a_{1},a_{2},.............,a_{n-1}$, where each $a_{i}$ is $0$ or $1$ ... $x$ and $y$ denote the degree of a vertex $G$ and number of connected component of $G$ for $n=8.$ The value of $x+10y$ is_____________
8
Which of the following graphs is/are planner?
9
Write the adjacency matrix representation of the graph given in below figure.
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11
How many ways are there to assign colours from range $\left\{1,2,\ldots,r\right\}$ to vertices of the following graph so that adjacent vertices receive distinct colours? $r^{4}$ $r^{4} - 4r^{3}$ $r^{4}-5r^{3}+8r^{2}-4r$ $r^{4}-4r^{3}+9r^{2}-3r$ $r^{4}-5r^{3}+10r^{2}-15r$
12
What is the chromatic number of the following graph? $2$ $3$ $4$ $5$
13
Total number of simple graphs that can be drawn using six vertices are: $2^{15}$ $2^{14}$ $2^{13}$ $2^{12}$
14
How many edges are there in a forest with $v$ vertices and $k$ components? $(v+1) - k$ $(v+1)/2 - k$ $v - k$ $v + k$
15
Which of the following is an advantage of adjacency list representation over adjacency matrix representation of a graph? In adjacency list representation, space is saved for sparse graphs. Deleting a vertex in adjacency list representation is easier than ... matrix representation. Adding a vertex in adjacency list representation is easier than adjacency matrix representation. All of the option.
16
Show that the number of odd-degree vertices in a finite graph is even.
17
The minimum number of colours required to colour the vertices of a cycle with $n$ nodes in such a way that no two adjacent nodes have the same colour is $2$ $3$ $4$ $n-2 \left \lfloor \frac{n}{2} \right \rfloor+2$
18
Degree of each vertex in $K_n$ is $n$ $n-1$ $n-2$ $2n-1$
19
The number of the edges in a regular graph of degree $’d’$ and $’n’$ vertices is Maximum of $n,d$ $n+d$ $nd$ $nd/2$
1 vote
20
If a planner graph, having $25$ vertices divides the plane into $17$ different regions. Then how many edges are used to connect the vertices in this graph. $20$ $30$ $40$ $50$
21
The number of ways to cut a six sided convex polygon whose vertices are labeled into four triangles using diagonal lines that do not cross is $13$ $14$ $12$ $11$
22
Maximum degree of any node in a simple graph with $n$ vertices is $n-1$ $n$ $n/2$ $n-2$
1 vote
23
Let $G$ be a simple undirected planar graph on $10$ vertices with $15$ edges. If $G$ is a connected graph, then the number of bounded faces in any embedding of $G$ on the plane is equal to: $3$ $4$ $5$ $6$
24
Given an undirected graph $G$ with $V$ vertices and $E$ edges, the sum of the degrees of all vertices is $E$ $2E$ $V$ $2V$
25
A path in graph $G$, which contains every vertex of $G$ and only once? Euler circuit Hamiltonian path Euler Path Hamiltonian Circuit
26
In a given following graph among the following sequences: abeghf abfehg abfhge afghbe Which are depth first traversals of the above graph? I,II and IV only I and IV only II,III and IV only I,III and IV only
27
Considering the following graph, which one of the following set of edged represents all the bridges of the given graph? $(a,b), (e,f)$ $(a,b), (a,c)$ $(c,d), (d,h)$ $(a,b)$
28
Which of the following statements is/are TRUE? $S1$:The existence of an Euler circuit implies that an Euler path exists. $S2$:The existence of an Euler path implies that an Euler circuit exists. $S1$ is true. $S2$ is true. $S1$ and $S2$ both are true. $S1$ and $S2$ both are false.
29
A connected planar graph divides the plane into a number of regions. If the graph has eight vertices and these are linked by $13$ edges, then the number of regions is: $5$ $6$ $7$ $8$
30
Let $G$ be a simple connected planar graph with $13$ vertices and $19$ edges. Then, the number of faces in the planar embedding of the graph is $6$ $8$ $9$ $13$
31
The number of diagonals that can be drawn by joining the vertices of an octagon is $28$ $48$ $20$ None of the option
32
Which of the following statements is/are TRUE for an undirected graph? Number of odd degree vertices is even Sum of degrees of all vertices is even P only Q only Both P and Q Neither P nor Q
33
Consider the following graph $L$ and find the bridges,if any. No bridge $\{d,e\}$ $\{c,d\}$ $\{c,d\}$ and $\{c,f\}$
34
The following graph has no Euler circuit because It has $7$ vertices. It is even-valent (all vertices have even valence). It is not connected. It does not have a Euler circuit.
35
For the graph shown, which of the following paths is a Hamilton circuit? $ABCDCFDEFAEA$ $AEDCBAF$ $AEFDCBA$ $AFCDEBA$
36
If $G$ is an undirected planar graph on $n$ vertices with $e$ edges then $e\leq n$ $e\leq 2n$ $e\leq 3n$ None of the option
37
Choose the most appropriate definition of plane graph. A simple graph which is isomorphic to hamiltonian graph. A graph drawn in a plane in such a way that if the vertex set of graph can be partitioned into two non-empty disjoint subset $X$ and $Y$ in such a way that each edge ... . A graph drawn in a plane in such a way that any pair of edges meet only at their end vertices. None of the option.
Let $G$ be a complete undirected graph on $8$ vertices. If vertices of $G$ are labelled, then the number of distinct cycles of length $5$ in $G$ is equal to: $15$ $30$ $56$ $60$
The number of edges in a complete graph with $‘n’$ vertices is equal to : $n(n-1)$ $\large\frac{n(n-1)}{2}$ $n^2$ $2n-1$
The number of edges in a complete graph with $N$ vertices is equal to : $N (N−1)$ $2N−1$ $N−1$ $N(N−1)/2$