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OA Exams

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  • November 12, 2024

Question 21

What is the result of performing breadth-first search (BFS) on a graph?

a) A tree that explores the graph by distance from the start vertex
b) A tree that explores the graph by depth from the start vertex
c) A tree that contains cycles
d) A tree that contains only isolated vertices

Correct Answer: a) A tree that explores the graph by distance from the start vertex

Explanation: Breadth-first search explores the graph by expanding the tree to include vertices that are closest to the start vertex.

Question 22

Which of the following best describes Prim’s algorithm?

a) It finds the shortest path between two vertices
b) It finds the minimum spanning tree by starting at a vertex and growing the tree by adding the smallest edge
c) It finds the maximum spanning tree by adding the largest edge
d) It finds the shortest cycle in a graph

Correct Answer: b) It finds the minimum spanning tree by starting at a vertex and growing the tree by adding the smallest edge

Explanation: Prim's algorithm is a greedy algorithm that finds the minimum spanning tree by starting at a vertex and adding the smallest possible edge to grow the tree.

Question 23

Which of the following is true for a matrix that has an inverse?

a) It is a singular matrix
b) It is a nonsingular matrix
c) It has parallel edges
d) It is a zero matrix

Correct Answer: b) It is a nonsingular matrix

Explanation: A nonsingular matrix is a square matrix that has an inverse, meaning it can be multiplied by another matrix to yield the identity matrix.

Question 24

Which of the following describes a diagonal matrix?

a) A square matrix where all diagonal entries are nonzero
b) A matrix where all entries are zero
c) A square matrix where all non-diagonal entries are zero
d) A matrix where all rows are equal

Correct Answer: c) A square matrix where all non-diagonal entries are zero

Explanation: A diagonal matrix is a square matrix where the only nonzero entries are along the main diagonal.

Question 25

Which of the following is a valid operation when multiplying matrices?

a) The number of columns in the first matrix must equal the number of rows in the second matrix
b) The number of rows in the first matrix must equal the number of columns in the second matrix
c) Both matrices must be square
d) Both matrices must have the same number of rows and columns

Correct Answer: a) The number of columns in the first matrix must equal the number of rows in the second matrix

Explanation: For matrix multiplication to be defined, the number of columns in the first matrix must match the number of rows in the second matrix.

Question 26

What is the identity matrix?

a) A matrix where all diagonal elements are zero
b) A diagonal matrix where all diagonal elements are 1
c) A square matrix where all elements are 1
d) A square matrix where all elements are zero

Correct Answer: b) A diagonal matrix where all diagonal elements are 1

Explanation: The identity matrix is a diagonal matrix with 1s on the diagonal and 0s elsewhere. It acts as the multiplicative identity in matrix multiplication.

Question 27

What is Gaussian elimination used for in matrix operations?

a) To find the inverse of a matrix
b) To reduce a matrix to row echelon form
c) To calculate the determinant of a matrix
d) To transpose a matrix

Correct Answer: b) To reduce a matrix to row echelon form

Explanation: Gaussian elimination is a method used to reduce a matrix to row echelon form by applying a series of row operations.

Question 28

What is the rank of a matrix?

a) The number of non-zero rows in its row echelon form
b) The number of rows in the matrix
c) The number of columns in the matrix
d) The number of zero rows in its row echelon form

Correct Answer: a) The number of non-zero rows in its row echelon form

Explanation: The rank of a matrix is the number of non-zero rows in its row echelon form, which represents the dimension of the row space.

Question 29

Which of the following describes an augmented matrix?

a) A matrix that includes an extra column representing the constants from a system of equations
b) A matrix where all rows have been multiplied by a scalar
c) A matrix where all elements are zero
d) A matrix where all elements are ones

Correct Answer: a) A matrix that includes an extra column representing the constants from a system of equations

Explanation: An augmented matrix is formed by appending the constant terms from a system of linear equations to the coefficient matrix.

Question 30

Which of the following is true for the sum of a finite geometric series?

a) It converges if the common ratio is less than 1
b) It diverges if the common ratio is less than 1
c) It converges if the common ratio is greater than 1
d) It diverges if the common ratio is greater than 1

Correct Answer: a) It converges if the common ratio is less than 1

Explanation: The sum of a finite geometric series converges if the common ratio is less than 1.

Question 31

Which of the following describes a harmonic series?

a) A series that converges to zero
b) A series that diverges to infinity
c) A series that oscillates between two values
d) A series that converges to a finite value

Correct Answer: b) A series that diverges to infinity

Explanation: A harmonic series grows very slowly but diverges to infinity.

Question 32

Which of the following is an example of an arithmetic sequence?

a) 1, 3, 5, 7, …
b) 1, 2, 4, 8, …
c) 2, 4, 8, 16, …
d) 1, 4, 9, 16, …

Correct Answer: a) 1, 3, 5, 7, ...

Explanation: An arithmetic sequence is one where each term is obtained by adding a constant value to the previous term, as in 1, 3, 5, 7, ...

Question 33

What is the common difference in the arithmetic sequence 2, 5, 8, 11, …?

a) 1
b) 2
c) 3
d) 4

Correct Answer: c) 3

Explanation: The common difference in this arithmetic sequence is 3, as each term is obtained by adding 3 to the previous term.

Question 34

Which of the following describes a geometric sequence?

a) A sequence in which each term is multiplied by a constant to obtain the next term
b) A sequence in which each term is subtracted by a constant to obtain the next term
c) A sequence in which each term is added by a constant to obtain the next term
d) A sequence in which each term is divided by a constant to obtain the next term

Correct Answer: a) A sequence in which each term is multiplied by a constant to obtain the next term

Explanation: A geometric sequence is one in which each term is obtained by multiplying the previous term by a constant factor.

Question 35

What is the explicit formula for the geometric sequence 3, 6, 12, 24, …?

a) an=3.2n−1
b) an=3.n
c) an=2.n+1
d) an=2n−1+33

Correct Answer: a) an=3.2n−1

Explanation: The explicit formula for a geometric sequence is an=a1.rn−1, where a1 is the first term and r is the common ratio.

Question 36

Which of the following best describes a finite series?

a) A series with a limited number of terms
b) A series with an infinite number of terms
c) A series that diverges to infinity
d) A series that oscillates between two values

Correct Answer: a) A series with a limited number of terms

Explanation: A finite series is a series that has a specific number of terms.

Question 37

Which of the following is true for the sum of an infinite geometric series?

a) It converges if the common ratio is less than 1
b) It converges if the common ratio is greater than 1
c) It diverges if the common ratio is less than 1
d) It diverges if the common ratio is greater than 1

Correct Answer: a) It converges if the common ratio is less than 1

Explanation: An infinite geometric series converges if the absolute value of the common ratio is less than 1.

Question 38

Which of the following is an example of a bijection?

a) A function that is injective and surjective
b) A function that is injective but not surjective
c) A function that is surjective but not injective
d) A function that is neither injective nor surjective

Correct Answer: a) A function that is injective and surjective

Explanation: A bijection is a function that is both injective (one-to-one) and surjective (onto).

Question 39

Which of the following is true for the inverse of a function?

a) It exists if the function is injective
b) It exists if the function is surjective
c) It exists if the function is bijective
d) It exists if the function is neither injective nor surjective

Correct Answer: c) It exists if the function is bijective

Explanation: A function has an inverse if it is bijective, meaning it is both injective and surjective.

Question 40

Which of the following is an example of an injective function?

a) A function where each element in the domain maps to a unique element in the codomain
b) A function where each element in the codomain maps to a unique element in the domain
c) A function where each element in the domain maps to multiple elements in the codomain
d) A function where each element in the codomain maps to multiple elements in the domain

Correct Answer: a) A function where each element in the domain maps to a unique element in the codomain

Explanation: An injective function is one where no two distinct elements in the domain map to the same element in the codomain.

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