#### 11th Standard Maths Matrices and Determinants English Medium Free Online Test One Mark Questions with Answer Key 2020 - 2021

11th Standard

Reg.No. :
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Maths

Time : 00:10:00 Hrs
Total Marks : 10

10 x 1 = 10
1. What must be the matrix X, if 2x+$\begin{bmatrix} 1& 2 \\ 3 & 4 \end{bmatrix}=\begin{bmatrix} 3 & 8 \\ 7 & 2 \end{bmatrix}?$

(a)

$\begin{bmatrix} 1& 3 \\ 2 &-1 \end{bmatrix}$

(b)

$\begin{bmatrix} 1& -3 \\ 2 &-1 \end{bmatrix}$

(c)

$\begin{bmatrix} 2& 6 \\ 4 &-2 \end{bmatrix}$

(d)

$\begin{bmatrix} 2& -6 \\ 4 &-2 \end{bmatrix}$

2. If the points (x,−2), (5, 2), (8,8) are collinear, then x is equal to

(a)

-3

(b)

${1\over 3}$

(c)

1

(d)

3

3. If the square of the matrix $\begin{bmatrix} \alpha & \beta \\ \gamma & -\alpha \end{bmatrix}$ is the unit matrix of order 2, then$\alpha ,\beta$ and $\gamma$ should satisfy the relation.

(a)

1+$\alpha ^2+\beta \gamma=0$

(b)

1-$\alpha ^2-\beta \gamma=0$

(c)

1-$\alpha ^2+\beta \gamma=0$

(d)

1+$\alpha ^2-\beta \gamma=0$

4. If A is skew-symmetric of order n and C is a column matrix of order n × 1, then CT AC is

(a)

an identity matrix of order n

(b)

an identity matrix of order 1

(c)

a zero matrix of order 1

(d)

an identity matrix of order 2

5. If A(B+C)=AB + AC where A, B, C are matrices of the same order than the property applied is matrix multipication is

(a)

commutative

(b)

association

(c)

(d)

distributive over multiplication

6. The product of any matrix by the scalar____________is the null matrix.

(a)

1

(b)

0

(c)

I

(d)

matrix itself

7. If A is a matrix 3 x 3, then ${ { (A }^{ 2 }) }^{ -1 }$=

(a)

$\frac { 1 }{ { A }^{ 2 } }$

(b)

A-2

(c)

${ { (A }^{ -1 }) }^{ 2 }$

(d)

I

8. If $\left( \begin{matrix} 2 & \lambda & -3 \\ 0 & 2 & 5 \\ 1 & 1 & 3 \end{matrix} \right)$ is a singular matrix, then $\lambda$ is

(a)

$\lambda$=2

(b)

$\lambda$≠2

(c)

$\lambda =\frac { -8 }{ 5 }$

(d)

$\lambda \neq \frac { -8 }{ 5 }$

9. Choose the incorrect statement

(a)

Matrix multiplication is non commutative

(b)

(c)

Singular matrices have inverse

(d)

Non singular matrices have inverse

10. If $\begin{bmatrix} 4 & 3 \\ -2 & x \end{bmatrix}$ is singular then the value of x is

(a)

$\frac{3}{2}$

(b)

-$\frac{3}{2}$

(c)

3

(d)

-2