๐Ÿซ CBSE FINAL PAPER

All India

Session Ending Examination 2022-23

๐Ÿ“˜ Class XI ยท Mathematics (041)

โฑ๏ธ 3 Hours ยท Max Marks: 80 ยท 5 Sections (A-E)

๐Ÿ“‹

๐Ÿ“Œ General Instructions
This question paper contains five sections A, B, C, D and E. Each section is compulsory. Internal choices in some questions.
Section A: 18 MCQs + 2 Assertion-Reason (1 mark each)
Section B: 5 VSA (2 marks each)
Section C: 6 SA (3 marks each)
Section D: 4 LA (5 marks each)
Section E: 3 Case-based (4 marks each)

๐Ÿ“ SECTION A

20 ร— 1 = 20 marks

Q1.
Sets

The set of all even natural numbers divisible by 5 is:

(A) Empty set

(B) Infinite set

(C) Singleton set

(D) Not a set

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (Infinite set)

๐Ÿ“ EXPLANATION: Even natural numbers divisible by 5 are multiples of 10: {10, 20, 30, …}. This set has infinitely many elements.

Q2.Set Theory

Let \(A\) and \(B\) be two sets in the same universal set. Then \(A – B =\)

(A) \(A \cap B\)

(B) \(A’ \cap B\)

(C) \(A \cap B’\)

(D) None of these

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (\(A \cap B’\))

๐Ÿ“ EXPLANATION: \(A – B\) represents elements in A but not in B, which is intersection of A with complement of B.

Q3.Sets

If a set contains 6 elements, then total number of proper subsets are:

(A) 65

(B) 64

(C) 63

(D) 32

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (63)

๐Ÿ“ EXPLANATION: Total subsets = \(2^6 = 64\). Proper subsets = total – 1 (excluding the set itself) = 63.

Q4.Ordered Pairs

If \((x + 1,1) = (3, y – 2)\) then \(x^{2} + y^{2}\) is:

(A) 5

(B) 13

(C) 9

(D) 4

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (13)

๐Ÿ“ EXPLANATION: Equate coordinates: \(x+1=3\) \(\Rightarrow x=2; 1=y-2\) \(\Rightarrow y=3\). Then \(x^2+y^2=4+9=13\).

Q5.Signum function

The range of the Signum function is:

(A) R

(B) N

(C) \(R^{+}\)

(D) \(\{-1,0,1\}\)

๐Ÿ” VIEW ANSWER

โœ… ANSWER: D ({-1,0,1})

Signum function returns -1 for negative, 0 for zero, 1 for positive.

Q6.Arc length

Length of arc of circle radius 5 cm subtending central angle 15ยฐ:

(A) \(\frac{\pi}{12}\) cm

(B) \(\frac{5\pi}{12}\) cm

(C) \(\frac{3\pi}{12}\) cm

(D) None

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (\(\frac{5\pi}{12}\) cm)

Arc length = \(\frac{\theta}{360ยฐ} \times 2\pi r \)\(= \frac{15}{360}\times 2\pi \times5 \)\(= \frac{1}{24}\times10\pi \)\(= \frac{5\pi}{12}\).

Q7.Trigonometry

If \(x\) in 3rd quadrant, \(\cos x = -\frac{12}{13}\), then \(\tan x\) =

(A) \(\frac{2}{13}\)

(B) \(\frac{5}{12}\)

(C) \(\frac{3}{4}\)

(D) -1

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (\(\frac{5}{12}\))

\(\sin^2 x = 1 – \frac{144}{169}\)\( = \frac{25}{169}\) โ‡’ \(\sin x = -\frac{5}{13}\) (3rd quadrant negative). Then \(\tan x = \frac{\sin x}{\cos x}\)\(= \frac{-5/13}{-12/13}\)\(= \frac{5}{12}\).

Q8.Complex Numbers

Standard form of \((5-3i)^3\) is:

(A) 10+198i

(B) 10-198i

(C) -10-198i

(D) None

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (-10-198i)

\((5-3i)^3 \)\(= 125 – 3\cdot25\cdot3i + 3\cdot5\cdot9i^2 – 27i^3\)\(= 125 -225i -135 +27i\)\(= -10 -198i\).

Q9.Inequalities

Solution set of \(\frac{1}{x-2}<0\) is:

(A) \((-\infty,2)\)

(B) \((-\infty,-2)\)

(C) \((-\infty,5)\)

(D) None

๐Ÿ” VIEW ANSWER

โœ… ANSWER: A (\((-\infty,2)\))

Fraction negative \(โ‡’ denominator negative\)\( โ‡’ x-2<0\) \(โ‡’x<2\).

Q10.Permutations

A gentleman has 6 friends to invite. In how many ways can he send invitation cards to them, if he has three servants to carry the cards?

(A)18

(B)216

(C)729

(D)1

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (729)

Each card can be given to any of 3 servants โ‡’ \(3^6 = 729\).

๐Ÿ“ SECTION A (Q11 – Q20)

10 ร— 1 = 10 marks

Q11.
๐Ÿงฎ Combinations

From a class of 32 students, 4 are to be chosen for a competition. In how many ways can this be done?

(A) 30560

(B) 35960

(C) 39560

(D) 35690

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (35960)

๐Ÿ“ EXPLANATION: Number of ways = \(C(32,4) = \frac{32 \times 31 \times 30 \times 29}{4 \times 3 \times 2 \times 1} \)\(= \frac{863040}{24}\)\( = 35960\).

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Q12.
๐Ÿ”ข Binomial Theorem

In the expansion of \((1 + x)^{20}\), total number of terms are:

(A) 20

(B) 0

(C) 21

(D) 19

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (21)

๐Ÿ“ EXPLANATION: In binomial expansion of \((1+x)^n\), number of terms = \(n+1\). Here n=20 โ‡’ 21 terms.

Q13.
๐Ÿ“ˆ AP

Sum of 20 terms of the A.P.: 1,4,7,… is:

(A) 650

(B) 590

(C) 200

(D) 59

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (590)

๐Ÿ“ EXPLANATION: First term a=1, common difference d=3. Sum \(S_n = \frac{n}{2}[2a + (n-1)d]\)\( = \frac{20}{2}[2(1) + 19\times3]\)\( = 10[2 + 57]\)\( = 10 \times 59\)\( = 590\).

Q14.
๐Ÿ“ 3D Geometry

The ratio in which the line joining (2,4,5) and (3,5,-9) is divided by the yz-plane is:

(A) 2:3

(B) 3:2

(C) -2:3

(D) 4:-3

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (-2:3)

๐Ÿ“ EXPLANATION: In yz-plane, x-coordinate = 0. Using section formula: \(0 = \frac{2 + 3k}{1+k}\) \(โ‡’ 2+3k=0\)\( โ‡’ k = -2/3 \)\(โ‡’ ratio -2:3 (externally).\)

Q15.
๐ŸŒ Octants

The point \((-5,3,2)\) lies in the:

(A) 2nd octant

(B) 7th octant

(C) X-Axis

(D) 5th octant

๐Ÿ” VIEW ANSWER

โœ… ANSWER: A (2nd octant)

๐Ÿ“ EXPLANATION: Signs: x negative, y positive, z positive โ†’ 2nd octant (as per standard octant numbering).

Q16.๐Ÿ“Š Statistics

Which of the following is not a measure of dispersion?

(A) Range

(B) Quartile deviation

(C) Standard Deviation

(D) Median

๐Ÿ” VIEW ANSWER

โœ… ANSWER: D (Median)

๐Ÿ“ EXPLANATION: Median is a measure of central tendency, not dispersion. Range, quartile deviation, and standard deviation measure spread.

Q17.๐ŸŽฒ Probability

If three coins are tossed together, probability of getting exactly 3 heads is:

(A) \(\frac{3}{8}\)

(B) \(\frac{1}{8}\)

(C) \(\frac{7}{8}\)

(D) \(\frac{1}{2}\)

๐Ÿ” VIEW ANSWER

โœ… ANSWER: B (\(\frac{1}{8}\))

๐Ÿ“ EXPLANATION: Total outcomes = \(2^3 = 8\). Favorable (HHH) = 1. Probability = \(\frac{1}{8}\).

Q18.๐Ÿ”ฒ Mutually Exclusive

If A and B are mutually exclusive events then \(P(A \cap B)\) is:

(A) 1

(B) \(\frac{1}{2}\)

(C) 0

(D) Not defined

๐Ÿ” VIEW ANSWER

โœ… ANSWER: C (0)

๐Ÿ“ EXPLANATION: Mutually exclusive events cannot occur simultaneously, so intersection is empty, probability = 0.

Q19.
โš–๏ธ Assertion-Reason

Assertion (A): The domain of the function \(f:A \rightarrow B\) is the set A.

Reason (R): The modulus function is defined for all real values. So the domain is the set of real numbers.

Choices:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

๐Ÿ” VIEW ANSWER

โœ… ANSWER: (a) Both A and R are true and R is the correct explanation of A.

๐Ÿ“ EXPLANATION: Assertion is true by definition of function domain. Reason is also true (modulus domain is all reals) and it correctly illustrates that domain can be set of real numbers, supporting the concept that domain is the set of inputs.

Q20.
โš–๏ธ Assertion-Reason

Assertion (A): The function which satisfies the condition \(f(-x) = f(x)\), is known as even function.

Reason (R): \(f(x) = \sin x\) is an even function.

Choices:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

๐Ÿ” VIEW ANSWER

โœ… ANSWER: (c) A is true but R is false.

๐Ÿ“ EXPLANATION: Assertion is correct definition of even function. Reason is false because \(\sin(-x) = -\sin x\), so sin x is odd, not even.

๐Ÿ“Œ solvedpapers.net

๐Ÿ† CBSE FINAL PAPER ยท Class 11 Mathematics 2022-23

โœ… Complete Section A (Q1-Q20) solutions ยท Answer key embedded ยท All steps explained

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