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#### 12th Standard Business Maths Applications of Matrices and Determinants English Medium Free Online Test One Mark Questions with Answer Key 2020 - 2021

12th Standard EM

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

10 x 1 = 10
1. The rank of m×n matrix whose elements are unity is

(a)

0

(b)

1

(c)

m

(d)

n

2. The rank of the unit matrix of order n is

(a)

n −1

(b)

n

(c)

n +1

(d)

n2

3. IfA =$\left( \begin{matrix} 1 \\ 2 \\ 3 \end{matrix} \right)$  then the rank of AAT is

(a)

0

(b)

1

(c)

2

(d)

3

4. The rank of the diagonal matrix$\left( \begin{matrix} 1 & & \\ & 2 & \\ & & -3 \end{matrix}\\ \quad \quad \quad \quad \quad \quad \quad \begin{matrix} 0 & & \\ & 0 & \\ & & 0 \end{matrix} \right)$

(a)

0

(b)

2

(c)

3

(d)

5

5. In a transition probability matrix, all the entries are greater than or equal to

(a)

2

(b)

1

(c)

0

(d)

3

6. The system of equations 4x+6y=5, 6x+9y=7 has

(a)

a unique solution

(b)

no solution

(c)

infinitely many solutions

(d)

none of these

7. Cramer’s rule is applicable only to get an unique solution when

(a)

${ \triangle }_{ z }\neq 0$

(b)

${ \triangle }_{ x }\neq 0$

(c)

${ \triangle }_\neq 0$

(d)

${ \triangle }_{ y }\neq 0$

8. The rank of an n x n matrix each of whose elements is 2 is

(a)

1

(b)

2

(c)

n

(d)

n2

9. If $\left| \begin{matrix} 2x & 5 \\ 8 & x \end{matrix} \right| =\left| \begin{matrix} 6 & -2 \\ 7 & 3 \end{matrix} \right|$ then x =

(a)

3

(b)

± 3

(c)

± 6

(d)

6

10. If A, B are two n x n non-singular matrices, then

(a)

AB is non-singular

(b)

AB is singular

(c)

(AB)-I = A-1 B-1

(d)

(AB)-1I does not exit