Graph Reconstruction

Description: Graph Reconstruction Quiz
Number of Questions: 15
Created by:
Tags: graph theory graph reconstruction
Attempted 0/15 Correct 0 Score 0

Which of the following is a necessary condition for a graph to be reconstructible?

  1. The degree sequence of the graph is unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The degree sequence of a graph is the sequence of the degrees of its vertices, arranged in non-decreasing order. If the degree sequence of a graph is unique, then the graph is reconstructible.

Which of the following is a sufficient condition for a graph to be reconstructible?

  1. The degree sequence of the graph is unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The degree sequence of a graph is the sequence of the degrees of its vertices, arranged in non-decreasing order. If the degree sequence of a graph is unique, then the graph is reconstructible.

Which of the following graphs is not reconstructible?

  1. A path graph

  2. A cycle graph

  3. A complete graph

  4. A star graph


Correct Option: D
Explanation:

A star graph is a tree with one central vertex and all other vertices connected to the central vertex. Star graphs are not reconstructible because their degree sequences are not unique.

Which of the following is a necessary condition for a graph to be uniquely reconstructible?

  1. The degree sequence of the graph is unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The degree sequence of a graph is the sequence of the degrees of its vertices, arranged in non-decreasing order. If the degree sequence of a graph is unique, then the graph is uniquely reconstructible.

Which of the following is a sufficient condition for a graph to be uniquely reconstructible?

  1. The degree sequence of the graph is unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The degree sequence of a graph is the sequence of the degrees of its vertices, arranged in non-decreasing order. If the degree sequence of a graph is unique, then the graph is uniquely reconstructible.

Which of the following graphs is uniquely reconstructible?

  1. A path graph

  2. A cycle graph

  3. A complete graph

  4. A star graph


Correct Option: A
Explanation:

A path graph is a tree with two end vertices and all other vertices having degree 2. Path graphs are uniquely reconstructible because their degree sequences are unique.

Which of the following is a necessary condition for a graph to be reconstructible from its edge degrees?

  1. The edge degrees of the graph are unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The edge degrees of a graph are the degrees of its edges, arranged in non-decreasing order. If the edge degrees of a graph are unique, then the graph is reconstructible from its edge degrees.

Which of the following is a sufficient condition for a graph to be reconstructible from its edge degrees?

  1. The edge degrees of the graph are unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The edge degrees of a graph are the degrees of its edges, arranged in non-decreasing order. If the edge degrees of a graph are unique, then the graph is reconstructible from its edge degrees.

Which of the following graphs is not reconstructible from its edge degrees?

  1. A path graph

  2. A cycle graph

  3. A complete graph

  4. A star graph


Correct Option: D
Explanation:

A star graph is a tree with one central vertex and all other vertices connected to the central vertex. Star graphs are not reconstructible from their edge degrees because their edge degree sequences are not unique.

Which of the following is a necessary condition for a graph to be uniquely reconstructible from its edge degrees?

  1. The edge degrees of the graph are unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The edge degrees of a graph are the degrees of its edges, arranged in non-decreasing order. If the edge degrees of a graph are unique, then the graph is uniquely reconstructible from its edge degrees.

Which of the following is a sufficient condition for a graph to be uniquely reconstructible from its edge degrees?

  1. The edge degrees of the graph are unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The edge degrees of a graph are the degrees of its edges, arranged in non-decreasing order. If the edge degrees of a graph are unique, then the graph is uniquely reconstructible from its edge degrees.

Which of the following graphs is uniquely reconstructible from its edge degrees?

  1. A path graph

  2. A cycle graph

  3. A complete graph

  4. A star graph


Correct Option: A
Explanation:

A path graph is a tree with two end vertices and all other vertices having degree 2. Path graphs are uniquely reconstructible from their edge degrees because their edge degree sequences are unique.

Which of the following is a necessary condition for a graph to be reconstructible from its Laplacian spectrum?

  1. The Laplacian spectrum of the graph is unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The Laplacian spectrum of a graph is the spectrum of its Laplacian matrix. If the Laplacian spectrum of a graph is unique, then the graph is reconstructible from its Laplacian spectrum.

Which of the following is a sufficient condition for a graph to be reconstructible from its Laplacian spectrum?

  1. The Laplacian spectrum of the graph is unique.

  2. The number of edges in the graph is even.

  3. The graph is connected.

  4. The graph is a tree.


Correct Option: A
Explanation:

The Laplacian spectrum of a graph is the spectrum of its Laplacian matrix. If the Laplacian spectrum of a graph is unique, then the graph is reconstructible from its Laplacian spectrum.

Which of the following graphs is not reconstructible from its Laplacian spectrum?

  1. A path graph

  2. A cycle graph

  3. A complete graph

  4. A star graph


Correct Option: D
Explanation:

A star graph is a tree with one central vertex and all other vertices connected to the central vertex. Star graphs are not reconstructible from their Laplacian spectra because their Laplacian spectra are not unique.

- Hide questions