Q: Incidence matrix and Adjacency matrix of a graph will always have same dimensions?
A. True
B. False
C. ..
D. ..
Solution: For a graph having V vertices and E edges, Adjacency matrix have V*V elements while Incidence matrix have V*E elements.
Q: The column sum in an incidence matrix for a simple graph is __________
A. depends on number of edges
B. always greater than 2
C. equal to 2
D. equal to the number of edges
Solution: For every edge only the vertices with which it is connected would have the value 1 in the matrix, as an edge connects two vertices sum will always be 2.
Q: What are the dimensions of an incidence matrix?
A. Number of edges*number of edges
B. Number of edges*number of vertices
C. Number of vertices*number of vertices
D. Number of edges * (1⁄2 * number of vertices)
Solution: Columns may represent edges and vertices may be represented by the rows.
Q: The column sum in an incidence matrix for a directed graph having no self loop is __________
A. 0
B. 1
C. 2
D. 0
Solution: Under every edge column there would be either all 0 values or a pair of -1 and +1 value exists.
Q: Time complexity to check if an edge exists between two vertices would be ___________
A. O(V*V)
B. O(V+E)
C. O(1)
D. O(E)
Solution: We have to check for all edges, in the worst case the vertices will have no common edge.