QB 060010212
QB 060010212
QB 060010212
2016
Unit-1: Matrix Algebra
Short questions answer
1. What is Matrix?
2. Define the following terms :
a) Elements matrix
b) Row matrix
c) Column matrix
d) Diagonal matrix
e) Scalar matrix
f) Unit matrix OR Identity matrix
g) Triangular matrix
h) Comparable matrices
i) Equality of matrices
j) Skew-symmetric matrix
3. If A is a matrix of order p × q and B is a matrix of order q × r, then what is the order of
the product of matrix AB?
4. What is the necessary condition for the addition of two matrices?
5. “Every identity matrix is a diagonal matrix” True or False? Justify your answer.
6. “Matrix multiplication is always commutative” True or False? Justify your answer.
7. What is necessary condition for matrix multiplication?
8. Find the inverse of matrix shown below.
2 0
0 0
9. State the difference between a matrix and a determinant.
10. List out special types of matrices.
11. Define inverse of a matrix.
12. Give the condition for the existence of the inverse.
13. List out the properties of the inverse of a matrix.
14. Which are the properties of the transpose of a matrix?
15. What do you mean by the principal diagonal of the matrix?
16. What is transpose of a matrix?
−3 8 3 −8
17. If A= and B= , find B-A.
3 5 3 −5
2 −3
18. If P= , find BT.
−1 9
1 0
19. If B = , find 2B and -3B.
4 7
2 3 5 1
20. If A= and B= , find AB and BA. Is AB=BA?
1 4 0 3
Long questions answer
7 3 −5
1. If A = 0 4 2 and B=3A; C=B+2A-5I. Find matrix D such that D=2A+B-C.
1 5 4
2. Determine whether the following graphs shown has directed or undirected edges,
whether it has multiple edges, or whether it has one or more loops?
a) b) c)
3. Does there exist, a simple graph with 5 vertices of the given degrees below? If so draw
4. Find the number of vertices, number of edges, and degree of each vertex in the
following undirected graphs. Identify all isolated and pendant vertices.
5. Find the number of vertices, number of edges, and degree of each vertex in the
following undirected graphs and hence, verify the Handshaking Theorem for each one:
6. Find the number of vertices, number of edges, in-degree and out-degree of each vertex
in the following directed graphs and hence, verify that the sum of in-degrees, the sum of
out degrees of the vertices and the number of edges in the following graphs are equal.
(g)
(h) (i)
3. Represent the incidence matrix for the following graphs:
(e)
(f) (g)
4. Determine whether the given graphs are isomorphic or not? Justify by giving appropriate
Reasons
(a)
(b)
(c)
(d)
(f)
(g) (h)
(i)
(j) (k)
(c) (d)
12. Draw a call graph for the telephone numbers 555-0011, 555-1221, 555-1333, 555-8888,
555-2222, 555-0091, and 555-1200 if there were three calls from 555-0011 to 555-8888,
two calls from 555-8888 to 555-0011 and two calls from 555-2222 to 555-0091 two calls
from 555-1221 to each of the other numbers, and one call from 555-1333 to each of
555-0011, 555-1221 and 555-1200
13. Draw the graphs represented by the following incidence matrices:
14. Give the step by step procedure of Dijktra’s algorithm to find the shortest path between
any two vertices.
15. Find the shortest path from the vertices a to z in the following graph model:
16. Find the shortest path for the graph model given below:
17. Find the shortest path from the vertices a to z in the following graph model:
18. Find the shortest path from the vertices a to z in the following graph model:
19. The diagram below shows roads connecting towns near to Rochdale. The numbers on
20. The diagram below shows roads connecting villages near to Royton. The numbers on
each arc represent the distance, in miles, along each road. Leon lives in Royton and
works in Ashton. Use Dijkstra’s algorithm to find the minimum distance for Leon’s
journey to work.
Multiple Choice Questions
1. A matrix whose rows are the rows of the unit matrix, but not necessarily in their natural
order, is called:
a) adjacency matrix
b) adjacency matrix of pseudo graph
c) adjacency matrix of simple graph
d) permutation matrix
2. If the edges in a path are distinct, it is called:
a) simple path
b) simple graph
c) length of the path
d) simple cycle
3. The maximum number of edges in a simple disconnected graph G with n vertices and k
components is:
a) (n-k)/2
b) (n-k+1)/2
2) Which of the given graphs are trees?
3) Answer the following questions about the rooted trees given below:
(a) Which vertex is the root? (b) Which vertices are internal?
(a) Which vertices are descendants of b?
(b) Is the rooted tree a full m-ary tree for some positive integer m?
(c) What is the level of each vertex of the rooted tree?
(d) Draw a sub-tree of the tree in the given tree figures that is rooted at (a) a; (b) c
6) How many edges does a tree with 10,000 vertices have?
7) How many vertices does a fully binary tree with 1000 internal vertices have?
8) How many leaves does a fully 3-ary tree with 100 vertices have?
9) How many edges does a full binary tree with 1000 internal vertices have?
10) Draw the sub tree of the tree that is rooted at “a, c, e”
11) Draw the sub tree of the tree that is rooted at “a, c, e”
12) What is the level of each vertex of the rooted tree
13) What is the level of each vertex of the rooted tree
14) Suppose there exists a simple connected graph with 16 vertices that has 15 edges. Does
it contain a vertex of degree 1? Justify your answer.
15) Draw a tree with two vertices of degree 3. Find the number of vertices of degree 1 in
your tree.
16) Draw a graph having the given properties or explain why no such graph exists.
a) Tree; six vertices having degree 1,1,1,1,3,3
b) Tree; all vertices of degree 2
c) Tree; 10 vertices and 10 edges
d) Connected graph; 7 vertices, 7 edges
e) Tree; 5 vertices, total degree of the vertices is 10
Multiple choice question
1. A tree is
A) Any graph that is connected and every edge is a bridge.
B) Any graph that has no circuits.
C) Any graph with one component.
D) Any graph that has no bridges.
2. Graph 1 is connected and has no circuits. Graph 2 is such that for any pair of vertices in the
graph there is one and only one path joining them.
A) Graph 1 cannot be a tree; Graph 2 cannot be a tree.
B) Graph 1 must be a tree; Graph 2 may or may not be a tree.
C) Graph 1 must be a tree; Graph 2 must be a tree.
D) Graph 1 must be a tree; Graph 2 cannot be a tree.
3. Suppose T is a tree with 21 vertices. Then
A) T has one bridge.
B) T has no bridges.
C) T can have any number of bridges.
D) T has 20 bridges.
4. In a tree between every pair of vertices there is?
A) Exactly one path
3. What is the purpose of Spanning Tree Protocol in a switched LAN?
4. What is Spanning tree?
5. Justify the statement” Every connected graph has a spanning tree.”
6. Assuming that G0 has a minimum spanning T0, is it true that the number of edges in the T0 no
greater than T? Answer yes or no and your answer explain in one sentence.
7. Assuming that G’ has a minimum spanning tree T’, by how many edges can T’ differ from T.
8. How many spanning tree does the following graph have?
9. How many spanning tree does the following graph have?
10. How many spanning trees does the following graph have?
11. Is the minimum weight edge in a graph always in any minimum spanning tree for a graph? Is
it always in any single source shortest path tree for the graph? Justify your answers.
12. Draw minimum spanning tree.
13. State whether your minimum spanning tree is unique.
14. State difference between following: Spanning Tree and minimum spanning tree
(a) Find all spanning trees.
(b) Find all spanning trees up to isomorphism.
(c) Find all depth-first spanning trees rooted at A.
(d) Find all depth-first spanning trees rooted at B.
5. For each of the following graphs:
(a) Find all minimum spanning trees.
(b) Find all minimum spanning trees up to isomorphism.
(c) Among all depth-first spanning trees rooted at A, find those of minimum weight.
(d) Among all depth-first spanning trees rooted at B, find those of minimum weight.
6. In the following graph, the edges are weighted either 1, 2, 3, or 4.
Referring to discussion following of Kruskal’s algorithm:
(a) Find a minimum spanning tree using Prim’s algorithm
(b) Find a minimum spanning tree using Kruskal’s algorithm.
(c) Find a depth-first spanning tree rooted at K.
7. Let T = (V,E) be a tree and let d(v) be the degree of a vertex
(a) Prove that Pv2V (2 − d(v)) = 2.
(b) Prove that, if T has a vertex of degree m 2, then it has at least m vertices of degree 1.
(c) Give an example for all m 2 of a tree with a vertex of degree m and only m leaves.
8. Does every connected graph have a spanning tree? Either give a proof or a counter-example.
9. Give an algorithm that determines whether a graph has a spanning tree, and finds such a tree
if it exists, that takes time bounded above by a polynomial in v and e, where v is the number of
vertices, and e is the number of edges.
11. Show that a finite graph is connected if and only if it has a spanning tree.
12. Find spanning tree of maximal (minimal) weights for graphs from figures using algorithms of
kruskal and prim.
13. Prove that every minimal spanning tree of a connected graph may be constructed by
kruskal’s algorithm.
14. Use Kruskal’s algorithm to find all least weight spanning trees for this weighted graph.
15. Find a minimum weight spanning tree in each of the following weighted graph
16. Find a minimum weight spanning tree in each of the following weighted graph
17. Draw all the spanning trees of K4.
18. Find the number of spanning trees in
19.
a. Use Kruskal’s algorithm to find a minimal spanning tree for the graph below.
b. Use Prim’s algorithm (as shown in class) to find a minimal spanning tree different
from the one in part
Multiple choice question
1. How many spanning trees does the following graph have?
A) 1
B) 2
C) 3
D) 4
The question(s) that follow refer to the problem of finding the minimum spanning tree for the
weighted graph shown below.
3. In Figure, using Kruskal's algorithm, which edge should we choose first?
A) AB
B) EG
C) BE
D) AG
4. In Figure, using Kruskal's algorithm, which edge should we choose third?
A) EF
B) AG
C) BG
D) EG
5. In Figure, using Kruskal's algorithm, which edge should we choose last?
A) AB
B) AC
C) CD
D) BC
6. In figure, which of the following edges of the given graph are not part of the minimum
spanning tree?
A) AC
B) EF
C) AG
D) BG
7. In Figure, the total weight of the minimum spanning tree is
A) 36.
B) 42.
C) 55.
D) 95.
8. Which of the following statements is true about Kruskal's algorithm.
A) It is an inefficient algorithm, and it never gives the minimum spanning tree.
B) It is an efficient algorithm, and it always gives the minimum spanning tree.
C) It is an efficient algorithm, but it doesn't always give the minimum spanning tree.
D) It is an inefficient algorithm, but it always gives the minimum spanning tree.
For the following question(s), refer to the digraph below.
9. In Figure, which of the following is not a path from vertex E to vertex B in the digraph?
A) E, B, C, B
B) E, D, B
C) E, A, B
D) E, A, C, B
10. The critical path algorithm is
A) An approximate and inefficient algorithm.
B) An optimal and efficient algorithm.
C) An approximate and efficient algorithm.
D) An optimal and inefficient algorithm.
11. Let w be the minimum weight among all edge weights in an undirected connected graph. Let
e be a specific edge of weight w. Which of the following is FALSE?
A) There is a minimum spanning tree containing e.
B) If e is not in a minimum spanning tree T then in the cycle formed by adding e to T, all
edges have the same weight.
C) Every minimum spanning tree has an edge of weight w.
D) e is present in every minimum spanning tree.
12. A minimal spanning tree of a graph G is....?
A) A spanning sub graph
B) A tree
C) Minimum weights
D) All of above
13. A tree having a main node, which has no predecessor is....?
A) Spanning tree
B) Rooted tree
B) Weighted tree
D) None of these
14. If a graph is a tree then
A) it has 2 spanning trees
B) it has only 1 spanning tree
C) it has 4 spanning trees
D) it has 5 spanning trees
15. Any two spanning trees for a graph
A) Does not contain same number of edges
B) Have the same degree of corresponding edges
C) contain same number of edges
D) May or may not contain same number of edges
16. A sub graph of a graph G that contains every vertex of G and is a tree is called
A) Trivial tree B) empty tree