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CBSE Class 12 Mathematics 2022 question paper (65/4)

Maximum marks 40 · Time 2 hours · 3 sets

Try each question first, then open its model answer. Where the paper offers a choice, both questions are shown with OR between them.

Section A

2 marks each

  1. Q.12 marks
    A bag contains 3 red and 4 white balls. Three balls are drawn at random, one-by-one without replacement from the bag. If the first ball drawn is red in colour, then find the probability that the remaining two balls drawn are also red in colour.
  2. Q.22 marks
    A coin is tossed twice. The following table shows the probability distribution of number of tails :
    X012
    P(X)K6K9K
    (a) Find the value of K. (b) Is the coin tossed biased or unbiased ? Justify your answer.
  3. Q.32 marks
    The foot of a perpendicular drawn from the point (−2,−1,−3)(-2, -1, -3) on a plane is (1,−3,3)(1, -3, 3). Find the equation of the plane.
  4. Q.4 (a)2 marks
    If ∣a⃗×b⃗∣2+∣a⃗⋅b⃗∣2=400|\vec{a} \times \vec{b}|^2 + |\vec{a} \cdot \vec{b}|^2 = 400 and ∣b⃗∣=5|\vec{b}| = 5, then find the value of ∣a⃗∣|\vec{a}|.
  5. OR

    Q.4 (b)2 marks
    Find all the possible vectors of magnitude 535\sqrt{3} which are equally inclined to the coordinate axes.
  6. Q.52 marks
    Find the general solution of the differential equation sec⁡2x⋅tan⁡y dx+sec⁡2y⋅tan⁡x dy=0.\sec^2 x \cdot \tan y \, dx + \sec^2 y \cdot \tan x \, dy = 0.
  7. Q.62 marks
    Evaluate : ∫01x2ex dx\displaystyle\int_0^1 x^2 e^x \, dx

Section B

3 marks each

  1. Q.73 marks
    Find the area of the region {(x,y):x2≤y≤x+2}\{(x, y) : x^2 \le y \le x + 2\}, using integration.
  2. Q.8 (a)3 marks
    Find : ∫1ex+1 dx\displaystyle\int \dfrac{1}{e^x + 1} \, dx
  3. OR

    Q.8 (b)3 marks
    Evaluate : ∫14{∣x∣+∣3−x∣} dx\displaystyle\int_1^4 \{|x| + |3 - x|\} \, dx
  4. Q.93 marks
    If a⃗\vec{a}, b⃗\vec{b} and c⃗\vec{c} are mutually perpendicular vectors of equal magnitude, then prove that the vector (2a⃗+b⃗+2c⃗)(2\vec{a} + \vec{b} + 2\vec{c}) is equally inclined to both a⃗\vec{a} and c⃗\vec{c}. Also, find the angle between a⃗\vec{a} and (2a⃗+b⃗+2c⃗)(2\vec{a} + \vec{b} + 2\vec{c}).
  5. Q.10 (a)3 marks
    If a line makes 60∘60^\circ and 45∘45^\circ angles with the positive directions of x-axis and z-axis respectively, then find the angle that it makes with the positive direction of y-axis. Hence, write the direction cosines of the line.
  6. OR

    Q.10 (b)3 marks
    Check whether the lines x−12=y−23=z−34\dfrac{x - 1}{2} = \dfrac{y - 2}{3} = \dfrac{z - 3}{4} and x−45=y−12=z\dfrac{x - 4}{5} = \dfrac{y - 1}{2} = z are skew or not.

Section C

  1. Q.114 marks
    Find the equations of the planes passing through the line of intersection of the planes r⃗⋅(i^+3j^)=6\vec{r} \cdot (\hat{i} + 3\hat{j}) = 6 and r⃗⋅(3i^−j^−4k^)=0\vec{r} \cdot (3\hat{i} - \hat{j} - 4\hat{k}) = 0, which are at a distance of 1 unit from the origin.
  2. Q.12 (a)4 marks
    Find the particular solution of the differential equation xdydx+y+11+x2=0x \dfrac{dy}{dx} + y + \dfrac{1}{1 + x^2} = 0, given that y(1)=0y(1) = 0.
  3. OR

    Q.12 (b)4 marks
    Find the general solution of the differential equation x(y3+x3) dy=(2y4+5x3y) dx.x (y^3 + x^3) \, dy = (2y^4 + 5x^3 y) \, dx.
  4. Q.134 marks
    Evaluate : ∫0π/2(2log⁡cos⁡x−log⁡sin⁡2x) dx\displaystyle\int_0^{\pi/2} (2 \log \cos x - \log \sin 2x) \, dx
  5. In a game of Archery, each ring of the Archery target is valued. The centremost ring is worth 10 points and rest of the rings are allotted points 9 to 1 in sequential order moving outwards. Archer A is likely to earn 10 points with a probability of 0⋅80{\cdot}8 and Archer B is likely the earn 10 points with a probability of 0⋅90{\cdot}9. Based on the above information, answer the following questions : If both of them hit the Archery target, then find the probability that
    Q.14 (a)2 marks
    exactly one of them earns 10 points.
  6. Q.14 (b)2 marks
    both of them earn 10 points.