1A matrix that has an equal number of rows and columns is called a:
types of matrices
Easy
A.Null matrix
B.Square matrix
C.Column matrix
D.Row matrix
Correct Answer: Square matrix
Explanation:
A square matrix has the same number of rows and columns, i.e., order .
Incorrect! Try again.
2A matrix in which all elements are zero is known as a:
types of matrices
Easy
A.Zero (null) matrix
B.Scalar matrix
C.Identity matrix
D.Diagonal matrix
Correct Answer: Zero (null) matrix
Explanation:
A zero or null matrix has every element equal to , e.g., .
Incorrect! Try again.
3The order of the matrix is:
types of matrices
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
The matrix has row and columns, so its order is . It is a row matrix.
Incorrect! Try again.
4A diagonal matrix in which all the diagonal elements are equal to is called a:
types of matrices
Easy
A.Identity matrix
B.Symmetric matrix
C.Triangular matrix
D.Scalar matrix
Correct Answer: Identity matrix
Explanation:
An identity matrix has on the main diagonal and elsewhere, denoted by .
Incorrect! Try again.
5If and , then is:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
Add corresponding elements: , , , .
Incorrect! Try again.
6Two matrices can be added only if they have the same:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Easy
A.Rank
B.Order
C.Determinant
D.Diagonal
Correct Answer: Order
Explanation:
Matrix addition requires both matrices to have the same number of rows and columns (same order).
Incorrect! Try again.
7If , then the transpose is:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
The transpose interchanges rows and columns, so rows of become columns of .
Incorrect! Try again.
8If , then equals:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
Scalar multiplication multiplies every element by : , , , .
Incorrect! Try again.
9The product of two matrices is defined only when the number of columns of equals the number of:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Easy
A.Rows of
B.Rows of
C.Columns of
D.Elements of
Correct Answer: Rows of
Explanation:
For to exist, columns of must equal rows of ; the product has order (rows of ) (columns of ).
Incorrect! Try again.
10The determinant of is:
determinant of second and third order
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
For a matrix, .
Incorrect! Try again.
11The value of is:
determinant of second and third order
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
For a diagonal matrix, the determinant is the product of the diagonal elements: .
Incorrect! Try again.
12If the determinant of a square matrix is zero, the matrix is called:
determinant of second and third order
Easy
A.Singular
B.Non-singular
C.Identity
D.Symmetric
Correct Answer: Singular
Explanation:
A matrix with is singular and does not have an inverse.
Incorrect! Try again.
13The determinant of the identity matrix is:
determinant of second and third order
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
. The determinant of any identity matrix is .
Incorrect! Try again.
14For , the adjoint of is:
adjoint and inverse of non-singular matrices of second and third order
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
For a matrix, the adjoint swaps the main diagonal elements and changes the sign of the off-diagonal elements.
Incorrect! Try again.
15The inverse of a matrix is given by the formula:
adjoint and inverse of non-singular matrices of second and third order
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
The inverse is the adjoint divided by the determinant, valid only when .
Incorrect! Try again.
16A matrix has an inverse only if it is:
adjoint and inverse of non-singular matrices of second and third order
Easy
A.Singular
B.Non-singular
C.A null matrix
D.A row matrix
Correct Answer: Non-singular
Explanation:
An inverse exists only when the determinant is non-zero, i.e., the matrix is non-singular.
Incorrect! Try again.
17If , then is:
adjoint and inverse of non-singular matrices of second and third order
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
Here and , so .
Incorrect! Try again.
18A system of linear equations can be solved using the inverse matrix as:
solution of system of linear equations using inverse of a matrix
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
Multiplying both sides of on the left by gives .
Incorrect! Try again.
19To solve the system using the inverse method, the coefficient matrix must be:
solution of system of linear equations using inverse of a matrix
Easy
A.A zero matrix
B.Non-singular
C.A row matrix
D.Singular
Correct Answer: Non-singular
Explanation:
The inverse exists only when , so must be non-singular to apply .
Incorrect! Try again.
20In Cramer's rule for two equations, the value of is given by , where Cramer's rule fails when:
application of determinant to solve simultaneous equations by cramer's rule
Easy
A.
B.
C.
D.
Correct Answer:
Explanation:
Cramer's rule requires dividing by , so it cannot be applied when the main determinant .
Incorrect! Try again.
21If a square matrix satisfies and all its diagonal elements are equal to a constant while all off-diagonal elements are zero, then is best described as a:
types of matrices
Medium
A.Singular matrix
B.Row matrix
C.Scalar matrix
D.Skew-symmetric matrix
Correct Answer: Scalar matrix
Explanation:
A diagonal matrix whose diagonal entries are all equal to the same constant is called a scalar matrix. It is a special case of a symmetric diagonal matrix.
Incorrect! Try again.
22For which value of is the matrix skew-symmetric?
types of matrices
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
A skew-symmetric matrix satisfies . This requires , so .
Incorrect! Try again.
23If and , then equals:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
. Subtracting : .
Incorrect! Try again.
24If and , then the product is:
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
Row-by-column: , , , . So .
Incorrect! Try again.
25For matrices and that are conformable for multiplication, which property is always true for the transpose of a product?
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
The transpose of a product reverses the order of the factors: . This is the reversal law for transpose.
Incorrect! Try again.
26If is a matrix and is a matrix, what is the order of the product ?
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Medium
A.
B.Not defined
C.
D.
Correct Answer:
Explanation:
The product is defined since the inner dimensions match (2 = 2). The resulting order takes the outer dimensions: .
Incorrect! Try again.
27The value of the determinant is:
determinant of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
For a determinant, value .
Incorrect! Try again.
28Evaluate the determinant .
determinant of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
For an upper triangular matrix, the determinant equals the product of the diagonal entries: .
Incorrect! Try again.
29For what value of is the matrix singular?
determinant of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
A matrix is singular when its determinant is zero. .
Incorrect! Try again.
30The value of the determinant is:
determinant of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
Expanding along the first row: .
Incorrect! Try again.
31If , then the adjoint of is:
adjoint and inverse of non-singular matrices of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
For a matrix, the adjoint swaps the diagonal entries and negates the off-diagonal entries: .
Incorrect! Try again.
32The inverse of is:
adjoint and inverse of non-singular matrices of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
. So .
Incorrect! Try again.
33For a non-singular square matrix of order , the relationship equals:
adjoint and inverse of non-singular matrices of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
By the fundamental adjoint property, , where is the identity matrix of the same order.
Incorrect! Try again.
34If for a matrix , then equals:
adjoint and inverse of non-singular matrices of second and third order
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
For an matrix, . Here , so .
Incorrect! Try again.
35The system , is written as . What is the coefficient matrix ?
solution of system of linear equations using inverse of a matrix
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
The coefficient matrix uses the coefficients of and from each equation as rows: .
Incorrect! Try again.
36For the matrix equation where is non-singular, the solution is given by:
solution of system of linear equations using inverse of a matrix
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
Multiplying both sides of by on the left gives , since matrix multiplication is not commutative.
Incorrect! Try again.
37Using the matrix inverse method, solve , . The solution is:
solution of system of linear equations using inverse of a matrix
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
Here , . Solving gives , , which satisfies both equations.
Incorrect! Try again.
38By Cramer's rule for , , the value of is given by , where is:
application of determinant to solve simultaneous equations by cramer's rule
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
is formed by replacing the -coefficient column of with the constants column, giving .
Incorrect! Try again.
39Using Cramer's rule, solve , . The value of is:
application of determinant to solve simultaneous equations by cramer's rule
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
, . So .
Incorrect! Try again.
40In Cramer's rule, if the determinant of the coefficient matrix equals zero while at least one of or is non-zero, then the system:
application of determinant to solve simultaneous equations by cramer's rule
Medium
A.Has no solution (inconsistent)
B.Has exactly two solutions
C.Has infinitely many solutions
D.Has a unique solution
Correct Answer: Has no solution (inconsistent)
Explanation:
When but a numerator determinant is non-zero, Cramer's rule fails and the system is inconsistent, meaning it has no solution.
Incorrect! Try again.
41If is a skew-symmetric matrix of order , then the value of is
types of matrices
Hard
A.
B.
C.
D.Depends on the entries of
Correct Answer:
Explanation:
For a skew-symmetric matrix , so . This gives , hence for any odd-order skew-symmetric matrix.
Incorrect! Try again.
42A matrix is called involutory if . Which of the following matrices is involutory?
types of matrices
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
Squaring gives . The second is idempotent (), the third is nilpotent (), and the fourth squares to .
Incorrect! Try again.
43If and , then equals
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
Row 1: . Row 2: , giving .
Incorrect! Try again.
44If is a matrix and is a matrix, what is the order of ?
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
has order . Transposing swaps the dimensions, so has order .
Incorrect! Try again.
45The value of is
determinant of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
Expanding along the first row: .
Incorrect! Try again.
46If , then the determinant obtained by multiplying every element of the second row by and then interchanging the first and third rows equals
determinant of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
Multiplying a row by multiplies the determinant by (giving ), and interchanging two rows changes the sign. Hence the result is .
Incorrect! Try again.
47The matrix is singular for
determinant of second and third order
Hard
A. or
B. or
C. or
D. or
Correct Answer: or
Explanation:
Singular means determinant : , so or .
Incorrect! Try again.
48The adjoint of is
adjoint and inverse of non-singular matrices of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
For a matrix , the adjoint is . Swapping the diagonal and negating the off-diagonal gives .
Incorrect! Try again.
49The inverse of is
adjoint and inverse of non-singular matrices of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
. Then .
Incorrect! Try again.
50If is a non-singular matrix with , then equals
adjoint and inverse of non-singular matrices of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
For an matrix, . Here , so .
Incorrect! Try again.
51If is a matrix with , then equals
determinant of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
For an matrix, . Here .
Incorrect! Try again.
52The inverse of is
adjoint and inverse of non-singular matrices of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
Solving for an upper-triangular unit-diagonal matrix gives entries , , and , so .
Incorrect! Try again.
53Using the matrix inverse method, the solution of is
solution of system of linear equations using inverse of a matrix
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
With , and . Then .
Incorrect! Try again.
54For the system , the value of obtained by Cramer's rule is
application of determinant to solve simultaneous equations by cramer's rule
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
Here and . Thus .
Incorrect! Try again.
55The system fails to have a unique solution when
application of determinant to solve simultaneous equations by cramer's rule
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
A unique solution requires , where . Setting gives , so the system has no unique solution at .
Incorrect! Try again.
56If , then equals
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Hard
A.The null matrix
B.The matrix
C.The identity matrix
D.The matrix
Correct Answer: The null matrix
Explanation:
, , . Then (Cayley–Hamilton).
Incorrect! Try again.
57The symmetric part of , given by , is
types of matrices
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
, so . Halving gives the symmetric part .
Incorrect! Try again.
58If is , is , and is , then the order of is
matrix operations (addition, subtraction, multiplication and transpose of matrices)
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
is , and multiplies a by a , giving order .
Incorrect! Try again.
59If and are matrices with and , then equals
determinant of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
and . Hence .
Incorrect! Try again.
60If is a matrix with , then equals
adjoint and inverse of non-singular matrices of second and third order
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
The fundamental identity gives .
Incorrect! Try again.
Did this save you a night before the exam?
LPU Notes is free, and it stays free. Ads cover part of the server bill.
The rest comes out of a student's own pocket: the domain, the storage,
and keeping the site up through the weeks everyone needs it at once.
The payment button didn't load. An ad blocker or a filtered network is the usual reason.
to try again.
Nothing here is ever locked, and nothing unlocks. Chip in only if it was worth it.
What it pays for →