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CBSE(NCERT) · Grade 12 · Maths

CBSE(NCERT) GRADE 12 MATHS 2023 SET2

42 questions from this Grade 12 Maths paper. Log in as a Grade 12 student to view solutions.

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Q1 mcq 1 mark
If for a square matrix $A$, $A^2 - 3A + I = O$ and $A^{-1} = xA + yI$, then the value of $x+y$ is:
  • A. 2
  • B. 2
  • C. 3
  • D. 3

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Q2 mcq 1 mark
If $|A| = 2$, where $A$ is a $2\times 2$ matrix, then $|4A^{-1}|$ equals:
  • A. 4
  • B. 2
  • C. 8
  • D. $\dfrac{1}{32}$

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Q3 mcq 1 mark
Let $A$ be a $3\times 3$ matrix such that $|\operatorname{adj} A| = 64$. Then $|A|$ is equal to:
  • A. 8 only
  • B. 8 only
  • C. 64
  • D. 8 or $-8$

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Q4 mcq 1 mark
If $A = \begin{pmatrix}2 & 5 \\ 4 & 3\end{pmatrix}$ and $2A + B$ is a null matrix, then $B$ is equal to:
  • A. $\begin{pmatrix}4 & 10 \\ 8 & 6\end{pmatrix}$
  • B. $\begin{pmatrix}4 & 10 \\ 8 & 6\end{pmatrix}$
  • C. $\begin{pmatrix}3 & 10 \\ 8 & 5\end{pmatrix}$
  • D. $\begin{pmatrix}3 & 10 \\ 8 & 5\end{pmatrix}$

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Q5 mcq 1 mark
If $\dfrac{d}{dx}(f(x)) = \log x$, then $f(x)$ equals:
  • A. $\dfrac{C}{x}$
  • B. $x(\log x - 1) + C$
  • C. $x(\log x + x) + C$
  • D. $\dfrac{C}{x}$

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Q6 mcq 1 mark
$\displaystyle \int_{0}^{6} x \sec^2 x\,dx$ is equal to:
  • A. $\dfrac{1}{3}$
  • B. $\dfrac{1}{3}$
  • C. $3$
  • D. $3$

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Q7 mcq 1 mark
The sum of the order and the degree of the differential equation $y\sin\left(\dfrac{dx}{dy}\right)^3 = 2x^2$ is:
  • A. 5
  • B. 2
  • C. 3
  • D. 4

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Q8 mcq 1 mark
The value of $p$ for which the vectors $2\hat{i} + p\hat{j} + \hat{k}$ and $4\hat{i} - 6\hat{j} + 26\hat{k}$ are perpendicular to each other, is:
  • A. 3
  • B. 3
  • C. $17/3$
  • D. $17/3$

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Q9 mcq 1 mark
$[(\hat{i}\times\hat{j})\cdot\hat{j} + (\hat{j}\times\hat{i})\cdot\hat{k}]$ का मान है:
  • A. 2
  • C. 1
  • D. 1

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Q9 mcq
The value of $(\hat{i}\times\hat{j})\cdot\hat{j}+(\hat{j}\times\hat{i})\cdot\hat{k}$ is:
  • A. 2
  • C. 1
  • D. 1

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Q10 mcq 1 mark
If $a+b=\hat{i}$ and $a=2\hat{i}-2\hat{j}+2\hat{k}$, then $|b|$ is equal to:
  • A. 14
  • B. 3
  • C. 12
  • D. 17

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Q10 mcq
If $\vec a+\vec b=\hat{i}$ and $\vec a=2\hat{i}-2\hat{j}+2\hat{k}$, then $|\vec b|$ equals:
  • A. 14
  • B. 3
  • C. 12
  • D. 17

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Q11 mcq 1 mark
The direction cosines of the line $\dfrac{x-1}{2} = \dfrac{y-1}{3} = \dfrac{z+1}{2}$ are:
  • A. $\dfrac{2}{7},\dfrac{3}{7},\dfrac{6}{7}$
  • B. $\dfrac{2}{157},\dfrac{3}{157},\dfrac{12}{157}$
  • C. $\dfrac{2}{7},\dfrac{3}{7},\dfrac{6}{7}$
  • D. $\dfrac{2}{7},\dfrac{3}{7},\dfrac{6}{7}$

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Q12 mcq 1 mark
If $P\left(\dfrac{A}{B}\right)=0.3$, $P(A)=0.4$ and $P(B)=0.8$, then $P(A\cap B)$ is equal to:
  • A. 0.6
  • B. 0.3
  • C. 0.06
  • D. 0.4

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Q12 mcq
If $P(B\mid A)=0.3$, $P(A)=0.4$ and $P(B)=0.8$, then $P(A\mid B)$ is equal to:
  • A. 0.6
  • B. 0.3
  • C. 0.06
  • D. 0.4

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Q13 mcq 1 mark
The value of $k$ for which $f(x)=2x,kx^2,5x^3$ is a constant function, is:
  • A. $\dfrac{4}{11}$
  • B. $\dfrac{11}{4}$
  • C. 11
  • D. $\dfrac{4}{11}$

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Q13 mcq
The value of $k$ for which $f(x)$ defined by $f(x)=\begin{cases}2x,&x<k\\kx^2,&x\ge k\end{cases}$ is a continuous function, is:
  • A. $\dfrac{4}{11}$
  • B. $\dfrac{11}{4}$
  • C. 11
  • D. $\dfrac{4}{11}$

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Q14 mcq
If $A=\begin{pmatrix}0&1\\1&0\end{pmatrix}$ and $(3I+4A)(3I-4A)=x^2I$, then the value(s) of $x$ is/are:
  • A. 7
  • C. 5
  • D. 25

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Q15 mcq
The general solution of the differential equation $x\,dy+(1+x^2)\,dx=dx$ is:
  • A. $y=2x+\dfrac{3}{x^3}+C$
  • B. $y=2\log x+\dfrac{3}{x^3}+C$
  • C. $y=\dfrac{2}{x^2}+C$
  • D. $y=2\log x+\dfrac{2}{x^2}+C$

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Q16 mcq
If $f(x)=a(x\cos x)$ is strictly decreasing in
  • A. {0}
  • B. $(0,\,)$
  • C. $(,0)$
  • D. $(,)$

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Q17 mcq
The corner points of the feasible region in the graphical representation of a linear programming problem are $(2,72)$, $(15,20)$ and $(40,15)$. If $z=18x+9y$ be the objective function, then:
  • A. $z$ is maximum at $(2,72)$, minimum at $(15,20)$
  • B. $z$ is maximum at $(15,20)$, minimum at $(40,15)$
  • C. $z$ is maximum at $(40,15)$, minimum at $(15,20)$
  • D. $z$ is maximum at $(40,15)$, minimum at $(2,72)$

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Q18 mcq
The number of corner points of the feasible region determined by the constraints $x\ge 0$, $y\ge 0$, $2y\le x+2$, $x\ge 0$, $y\ge 0$ is:
  • A. 2
  • B. 3
  • C. 4
  • D. 5

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Q19 mcq 1 mark
Assertion (A): The range of $f(x)=2\sin^{-1}x+\dfrac{2}{3}$, $x\in[-1,1]$, is $\left[-\dfrac{2}{5},\dfrac{2}{5}\right]$. Reason (R): The principal value range of $\sin^{-1}(x)$ is $\left[0,\,\right]$.
  • A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • C. Assertion (A) is true and Reason (R) is false.
  • D. Assertion (A) is false and Reason (R) is true.

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Q20 mcq 1 mark
Assertion (A): Equation of a line passing through the points $(1,2,3)$ and $(3,1,3)$ is $\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{0}$. Reason (R): Equation of a line passing through points $(x_1,y_1,z_1)$, $(x_2,y_2,z_2)$ is given by $\dfrac{x-x_1}{x_2-x_1}=\dfrac{y-y_1}{y_2-y_1}=\dfrac{z-z_1}{z_2-z_1}$.
  • A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • C. Assertion (A) is true and Reason (R) is false.
  • D. Assertion (A) is false and Reason (R) is true.

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Q21 short answer 2 marks
A function $f:A\to B$ defined as $f(x)=2x$ is both one-one and onto. If $A=\{1,2,3,4\}$, then find the set $B$. OR Evaluate: $\sin^{-1}\!\left(\frac{4}{3}\sin\left(\frac{1}{4}\right)+\cos\left(\frac{4}{3}\right)+\tan^{-1}(1)\right)$

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Q22 short answer 2 marks
Find all the vectors of magnitude $3\sqrt{3}$ which are collinear to vector $\hat{i}+\hat{j}+\hat{k}$.

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Q23 short answer 2 marks
Position vectors of the points $A$, $B$ and $C$ as shown in the figure below are $\vec a$, $\vec b$ and $\vec c$ respectively. If $AC=\dfrac{4}{5}AB$, express $\vec c$ in terms of $\vec a$ and $\vec b$. OR Find whether the lines $x=2+2\lambda$, $y=7+\lambda$, $z=3-3\lambda$ and $x=2$, $y=2+8\mu$, $z=4+5\mu$ are perpendicular to each other or not.

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Q24 short answer 2 marks
If $y=\left(x+\frac{1}{x^2}\right)^2$, then show that $(x^2-1)^2\dfrac{dy}{dx}=4y^2$.

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Q25 short answer 2 marks
Show that the function $f(x)=\dfrac{x\cos^4 x}{x\sin^{16} x}$ is strictly decreasing in $\left(0,\dfrac{\pi}{2}\right)$.

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Q26 short answer 3 marks
Evaluate: $\int_0^2 [\log(\sin x)+\log(2\cos x)]\,dx$.

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Q27 short answer 3 marks
Find: $\int \dfrac{1}{(1+x)(1+2x)}\,dx$.

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Q28 short answer 3 marks
Find the particular solution of the differential equation $\dfrac{dy}{dx}+\sec^2 x\, y=\tan x\,\sec^2 x$, given that $y(0)=0$. OR Solve the differential equation given by $x\,dy-y\,dx=(2x^2+y^2)\,dx=0$.

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Q29 long answer
Solve graphically the following linear programming problem: Maximise $z=6x+3y$, subject to the constraints $4x+y\le 80$, $3x+2y\le 150$, $x+5y\le 115$, $x\ge 0$, $y\ge 0$.

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Q30 short answer
A random variable $X$ has the following probability distribution: $\begin{array}{c|ccc} X & 1 & 2 & 3 \\ \hline P(X) & 2k & 3k & 6k \end{array}$ (i) Find the value of $k$. (ii) Find $P(1<X<3)$. (iii) Find the mean $E(X)$. OR If $A$ and $B$ are two independent events such that $P(A\cup B)=\dfrac{1}{4}$ and $P(A\cap B)=\dfrac{1}{6}$, find $P(A)$ and $P(B)$.

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Q31 short answer
Evaluate: $\int_0^2 e^x\sin x\,dx$ OR Find: $\int \bigl(bx\cos x + ax\cos x\bigr)\,dx$

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Q32 long answer 5 marks
A relation $R$ is defined on a set of real numbers as $R=\{(x,y): x\cdot y$ is an irrational number$\}$. Check whether $R$ is reflexive, symmetric and transitive or not.

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Q33 long answer 5 marks
(a) If $A=\begin{pmatrix}1&2&0\\3&2&1\\0&1&2\end{pmatrix}$ and $B=\begin{pmatrix}1&3&2\\5&1&6\\1&5&2\end{pmatrix}$, find $(AB)^{-1}$. OR (b) Solve the following system of equations by matrix method: $x+2y+3z=6$ $2x-y+z=2$ $3x+2y-2z=3$

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Q34 long answer 5 marks
(a) Find the vector and the Cartesian equations of a line passing through the point $(1,2,4)$ and parallel to the line joining the points $A(3,3,5)$ and $B(1,0,11)$. Hence, find the distance between the two lines. OR (b) Find the equations of the line passing through the points $A(1,2,3)$ and $B(3,5,9)$. Hence, find the coordinates of the points on this line which are at a distance of 14 units from point $B$.

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Q35 long answer 5 marks
Find the area of the region bounded by the curves $x^2=y$, $y=x+2$ and the $x$-axis, using integration.

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Q36 short answer
There are different types of Yoga which involve the usage of different poses of Yoga Asanas, Meditation and Pranayam as shown in the figure below: Types of Yoga Hatha Yoga Bikram Yoga Vinyasa Yoga Kundalini Yoga Anusara Yoga

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Reading Passage

The Venn diagram below represents the probabilities of three different types of Yoga, A, B and C performed by the people of a society. Further, it is given that probability of a member performing type C Yoga is 0·44. On the basis of the above information, answer the following questions :

Q41 short answer 2 marks
Find the probability that a randomly selected person of the society does Yoga of type A or B but not C.

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Reading Passage

The equation of the path traced by a roller-coaster is given by the polynomial $f(x) = a(x + 9)(x + 1)(x - 3)$. If the roller-coaster crosses y-axis at a point $(0, 1)$, answer the following :

Q42 short answer 2 marks
Find $f(x)$ at $x = 1$.

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