#### 12th Standard Maths English Medium Free Online Test Creative One Mark Questions with Answer Key - Part Four

12th Standard

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Maths

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

Answer all the questions

10 x 1 = 10
1. If ATA−1 is symmetric, then A2 =

(a)

A-1

(b)

(AT)2

(c)

AT

(d)

(A-1)2

2. Every homogeneous system ______

(a)

Is always consistent

(b)

Has only trivial solution

(c)

Has infinitely many solution

(d)

Need not be consistent

3. If A is a non-singular matrix then IA-1|= ______

(a)

$\left| \frac { 1 }{ { A }^{ 2 } } \right|$

(b)

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

(c)

$\left| \frac { 1 }{ A } \right|$

(d)

$\frac { 1 }{ |A| }$

4. If x+iy =$\frac { 3+5i }{ 7-6i }$, they y =

(a)

$\frac { 9 }{ 85 }$

(b)

-$\frac { 9 }{ 85 }$

(c)

$\frac { 53 }{ 85 }$

(d)

none of these

5. If x + y = 8, then the maximum value of xy is _________

(a)

8

(b)

16

(c)

20

(d)

24

6. If u = y sin x then $\frac { { \partial }^{ 2 }u }{ \partial x\partial y }$ = ..........

(a)

cos x

(b)

cos y

(c)

sin x

(d)

0

7. $\int _{ -\frac { \pi }{ 2 } }^{ \frac { \pi }{ 2 } }{ \frac { sinx }{ 2+cosx } dx= }$

(a)

0

(b)

2

(c)

log 2

(d)

log 4

8. The differential equation corresponding to xy=c2 where c is an arbitrary constant is ________.

(a)

xy"+x=0

(b)

y"=0

(c)

xy'+y=0

(d)

xy"-x=0

9. If $f(x)=\cfrac { 1 }{ 2 }$ ,$E\left( { x }^{ 2 } \right) =\cfrac { 1 }{ 4 }$ then var(x) is

(a)

0

(b)

$\cfrac { 1 }{ 4 }$

(c)

$\cfrac { 1 }{ 2 }$

(d)

1

10. In (S, *), is defined by x * y = x where x, y $\in$ S, then

(a)

associative

(b)

Commutative

(c)

associative and commutative

(d)

neither associative nor commutative