For a simple undirected graph, the adjacency matrix is symmetric.
09 Introduction to Graph Theory Online Quiz Questions
Use this free practice quiz with 20 questions to review 09 Introduction to Graph Theory, test your knowledge, and prepare for your next test or exam.
A simple undirected graph has edges xy, xz, and xw incident with vertex x, and no other edge incident with x. What is deg(x)?
Complete each definition. A walk that does not repeat an edge is a . A walk that does not repeat a vertex is a .
Let G have vertex set V={a,b,c,d} and edge set E={ab,bc,cd}. Which graph is a spanning subgraph of G?
- A
H=({a,b,c},{ab,bc})
- B
H=({a,b,c,d},{ab,bc,cd,da})
- C
H=({a,b,c,d},{ab,bc})
- D
H=({a,b},{ab})
Which statements correctly describe graph representations or their uses? Select all that apply.
- A
An adjacency list is often memory-efficient for a sparse graph.
- B
An adjacency matrix is always more memory-efficient than an adjacency list for a sparse graph.
- C
An edge list directly records the graph's edges.
- D
An adjacency list must contain a separate matrix row for every pair of vertices.
If a graph is connected, then there is exactly one path between every pair of vertices.
- A
True
- B
False
A graph has edges uv, vw, wz, and vz. What is the distance d(u,z), measured as the number of edges in a shortest path?
Complete each statement. A connected graph with no cycles is a . A vertex with degree zero is .
A simple graph has edges ab, bc, cd, da, and ac. Which sequence is a cycle?
- A
a,b,c,a,d
- B
a,b,c,d,a
- C
a,b,a,c
- D
a,c,b,d
In an undirected graph, a loop contributes 2 to the degree of its incident vertex.
- A
True
- B
False
A graph has vertex set {a,b,c,d,e,f} and edge set {ab,bc,de}. Select all of its connected components, giving each component by its vertex set.
- A
{a,b,c}
- B
{d,e}
- C
{f}
- D
{a,b,c,d,e,f}
Explain the difference between a spanning subgraph and an induced subgraph. Include what each must retain from the original graph and why a subgraph with the same selected vertices might fail to be induced.
In an incidence matrix for a simple undirected graph, what does one column represent?
- A
A column lists all neighbors of one vertex.
- B
A column identifies the two endpoints of one edge.
- C
A row gives the degree sequence of the graph.
- D
A row records whether the graph is connected.
A simple undirected graph is represented by an adjacency matrix. Which property must the matrix have?
- A
Every entry on the diagonal must be 1.
- B
The matrix must be symmetric.
- C
Every row must contain the same number of 1s.
- D
The matrix must have more 1s than 0s.
For the graph V={a,b,c,d} with E={ab,ac,bc,cd}, which is the degree sequence when written in nonincreasing order?
- A
(2,2,3,1)
- B
(4,2,1,1)
- C
(3,2,2,1)
- D
(3,3,1,1)
A graph has vertex set {a,b,c,d,e} and edges ab,bc,de. How many connected components does it have?
In a graph containing the edges ab and bc, how should the vertex sequence a,b,c,b be classified?
- A
A path, trail, and walk
- B
A walk but neither a trail nor a path
- C
A trail but not a path or walk
- D
Neither a walk, trail, nor path
Which graph representation is usually efficient for a sparse graph because it records only the neighbors that each vertex actually has?
Let G have V={a,b,c,d} and E={ab,ac,bc,cd}. Which edge set must the subgraph induced by W={a,b,c} contain?
- A
Only ab
- B
ab and bc only
- C
ab, ac, and bc
- D
ab, ac, bc, and cd
Which number of odd-degree vertices could a finite undirected graph have?
- A
3
- B
5
- C
7
- D
8