CUET PG Mathematics Question Paper 2024 is available here for download. NTA is conducting CUET PG 2024 from March 11 to March 28. CUET PG Question Paper 2024 is based on objective-type questions (MCQs). According to latest exam pattern, candidates get 105 minutes to solve 75 MCQs in CUET PG 2024 Mathematics question paper.

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Mathematics 2024 Questions with Solutions

Question 1:

The solution of the differential equation x(dy/dx) + y = x^3 y^6 is: (where C is an arbitrary constant)

  1. y-5x-5 = (5/2)x-2 + C
  2. y-5x-2 = (5/2)x-2 + C
  3. y-5x-5 = (5/2)x-5 + C
  4. y-2x-5 = (5/2)x-2 + C
Correct Answer: (a) y = (5/2)x-2 + C.
View Solution

This differential equation is solved using the separable variable technique. Rewrite the equation as:

x(dy/dx) + y = x3 y6.

Separate the variables y and x, and integrate to solve. After solving, we obtain:

y = (5/2)x-2 + C.

Final Answer: y = (5/2)x-2 + C.


Question 2:

If the eigenvalues of a 3x3 matrix are 6, 5, and 2, what is the determinant of (A-1)7?

  1. 0.005
  2. 0.0087
  3. 0.506
  4. 0.016
Correct Answer: (d) 0.016.
View Solution

The determinant of A, a 3x3 matrix, is the product of its eigenvalues:

det(A) = 6 x 5 x 2 = 60.

The determinant of A-1 is the reciprocal of det(A):

det(A-1) = 1/60.

For (A-1)7, the determinant is:

det((A-1)7) = (det(A-1))7 = (1/60)7 = 0.016.

Final Answer: 0.016


Question 3:

Let S denote the set of all real numbers except -1. Define the binary operation * on S as a * b = a + b + ab. Then the solution of the equation 2 * x * 3 = 7 is:

  1. -1/3
  2. -1/2
  3. 7/5
  4. 7/6
Correct Answer: (a) -1/3.
View Solution

Using the definition a * b = a + b + ab, simplify the expression:

2 * x = 2 + x + 2x.

Substitute 2 * x into the second operation (2 * x) * 3:

(2 + x + 2x) * 3 = (2 + x + 2x) + 3 + (2 + x + 2x) x 3.

Simplify to solve for x:

x = -1/3.

Final Answer: x = -1/3.


Question 4:

Let W be the Wronskian of two linearly independent solutions of the differential equation 2y'' + y' + t2y = 0. Then for all t, there exists a constant C such that W(t) is:

  1. Cet
  2. Ce-t/2
  3. Ce2t
  4. Ce-2t
Correct Answer: (b) Ce-t/2.
View Solution

Using Abel's formula for the Wronskian:

W(t) = Ce-∫p(t) dt, where p(t) is the coefficient of y'.

Here, p(t) = 1/2. Integrating p(t):

W(t) = Ce-t/2.

Final Answer: Ce-t/2.


Question 5:

The equation sin(z) = 10 has:

  1. A unique solution
  2. Exactly two distinct complex solutions
  3. Infinitely many complex solutions
  4. No solution
Correct Answer: (c) Infinitely many complex solutions.
View Solution

For sin(z) = 10, z must be a complex number because sin(z) exceeds its real range [-1, 1].

The equation sin(z) = 10 can be expressed as:

sin(z) = (eiz - e-iz)/(2i) = 10.

This leads to infinitely many solutions due to the periodicity of sine in the complex plane.

Final Answer: Infinitely many complex solutions.


Question 6:

Match List-I with List-II:

List-I (Differential Equation) List-II (Particular Integral)
(A) (D2 + 6D + 9)y = ex (I) (2/13)exsin(2x) + (10/13)excos(2x)
(B) (D2 - 3D - 4)y = 2sin(x) (II) ex/16
(C) (D2 - 3D - 4)y = -8excos(2x) (III) -2/5 xe-x
(D) (D2 - 3D - 4)y = 2e-x (IV) -5/17 sin(x) + 3/17 cos(x)

Choose the correct answer from the options below:

  1. (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
  2. (A) - (II), (B) - (III), (C) - (I), (D) - (IV)
  3. (A) - (III), (B) - (II), (C) - (IV), (D) - (I)
  4. (A) - (IV), (B) - (III), (C) - (I), (D) - (II)
Correct Answer: (b) (A) - (II), (B) - (III), (C) - (I), (D) - (IV).
View Solution

We analyze each differential equation and calculate its particular integral (PI) using the method of undetermined coefficients:

(A) (D2 + 6D + 9)y = ex: PI = ex/16.

(B) (D2 - 3D - 4)y = 2sin(x): PI = (2/13)exsin(2x) + (10/13)excos(2x).

(C) (D2 - 3D - 4)y = -8excos(2x): PI = -5/17 sin(x) + 3/17 cos(x).

(D) (D2 - 3D - 4)y = 2e-x: PI = -2/5 xe-x.

Final Answer: (b) (A) - (II), (B) - (III), (C) - (I), (D) - (IV).


Question 7:

Let W be a solution space of the differential equation d2y/dx2 + 6dy/dx + 11dy/dx + 6y = 0. Then the dimension of the solution space W is:

  1. 2
  2. 3
  3. 1
  4. 4
Correct Answer: (a) 2.
View Solution

The given differential equation is of second order. The solution space of a linear differential equation corresponds to the order of the equation, which defines the number of linearly independent solutions.

As the equation is of order 2, the dimension of the solution space W is 2.

Final Answer: 2.


Question 8:

Tricomi's equation uxx + x uyy = 0 is:

  1. Elliptic for x < 0
  2. Hyperbolic for x < 0
  3. Parabolic for x > 0
  4. Both parabolic and hyperbolic for x > 0
Correct Answer: (b) Hyperbolic for x < 0.
View Solution

Tricomi's equation changes type depending on the value of x:

For x < 0, it is hyperbolic. For x > 0, it is elliptic. At x = 0, it is parabolic.

Final Answer: Hyperbolic for x < 0.


Question 9:

The set on which f(x) = x2 is uniformly continuous is:

  1. [-1, 1]
  2. (-1, 1)
  3. R
  4. Nowhere
Correct Answer: (a) [-1, 1].
View Solution

The function f(x) = x2 is uniformly continuous on the closed interval [-1, 1].

Uniform continuity fails on R due to unbounded growth at infinity.

Final Answer: [-1, 1].


Question 10:

Which of the following is a subspace of R3?

  1. W = {(x, y, z) in R3 : x + 4y - 10z = -2}
  2. W = {(x, y, z) in R3 : xy = 0}
  3. W = {(x, y, z) in R3 : 2x + 3y - 4z = 0}
  4. W = {(x, y, z) in R3 : x in Q}
Correct Answer: (c) W = {(x, y, z) in R3 : 2x + 3y - 4z = 0}.
View Solution

For a subset W of R3 to be a subspace, it must satisfy:

1. W contains the zero vector.

2. W is closed under vector addition.

3. W is closed under scalar multiplication.

Options (a), (b), and (d) fail one or more of these criteria, whereas (c) satisfies all.

Final Answer: W = {(x, y, z) in R3 : 2x + 3y - 4z = 0}.


Question 11:

If ∫(0 to 2a) x³√(2ax - x²) dx = (p/q)πa⁵, then p² + q² is equal to:

  1. 113
  2. 103
  3. 131
  4. 301
Correct Answer: (a) 113.
View Solution

We are given the integral ∫(0 to 2a) x³√(2ax - x²) dx = (p/q)πa⁵. After solving using substitution techniques:

We find p = 7 and q = 2. Calculating p² + q²:

p² + q² = 7² + 2² = 49 + 64 = 113.

Final Answer: 113.


Question 12:

The orthogonal trajectory of the equation x² + y² = C, where C is an arbitrary constant, is:

  1. y = C/x
  2. y = Cx
  3. x² - y² = C
  4. y = Cx³
Correct Answer: (b) y = Cx.
View Solution

The orthogonal trajectory of x² + y² = C is obtained by differentiating and using the orthogonality condition dy/dx × (-x/y) = -1.

Solving this differential equation gives y = Cx.

Final Answer: y = Cx.


Question 13:

Which of the following statements is not correct?

  1. There is a one-to-one correspondence between any two right cosets of the subgroup H in group G.
  2. If H, K are subgroups of G, then HK is a subgroup of G if and only if HK = KH.
  3. If H, K are subgroups of the abelian group G, then HK is a subgroup of G.
  4. If H, K are subgroups of G, then H ∩ K may or may not be a subgroup of G.
Correct Answer: (d) H ∩ K may or may not be a subgroup of G.
View Solution

In group theory, the intersection H ∩ K of subgroups H and K is always a subgroup of G.

Thus, the statement "H ∩ K may or may not be a subgroup of G" is incorrect.

Final Answer: (d).


Question 14:

The points on the sphere x² + y² + z² = 1 which are at the maximum and minimum distance from the point (3, 4, 12) are:

  1. Point A(4/13, 12/13, 12/13) at maximum distance and Point B(-3/13, -4/13, -12/13) at minimum distance.
  2. Point A(3/13, 4/13, 12/13) at minimum distance and Point B(-3/13, -4/13, -12/13) at maximum distance.
  3. Point A(4/13, 12/13, 4/13) at minimum distance and Point B(-3/13, 4/13, -12/13) at maximum distance.
  4. Point A(12/13, -12/13, -4/13) at minimum distance and Point B(-3/13, -4/13, 12/13) at maximum distance.
Correct Answer: (b).
View Solution

To find the points of maximum and minimum distance from a given point to a sphere, use the distance formula.

After computation, Point A(3/13, 4/13, 12/13) is at the minimum distance, and Point B(-3/13, -4/13, -12/13) is at the maximum distance.

Final Answer: (b).


Question 15:

For which value of k, the function f(x) = {kx², x ≥ 1; 4, x < 1} is continuous at x = 1?

  1. k = 1
  2. k = 2
  3. k = 3
  4. k = 4
Correct Answer: (d) k = 4.
View Solution

To check continuity at x = 1, equate the left-hand limit lim(x → 1⁻) f(x) = 4 and the right-hand limit lim(x → 1⁺) f(x) = k.

Solving k = 4, we find the function is continuous at x = 1.

Final Answer: k = 4.


Question 16:

If a linear transformation T: R² → R³ is defined by T(1,2) = (3,2,1) and T(3,4) = (6,5,4), then T(1,0) is:

  1. (0,1,2)
  2. (1,0,2)
  3. (-1,0,2)
  4. (2,1,-1)
Correct Answer: (a) (0,1,2).
View Solution

To find T(1,0), express (1,0) as a linear combination of (1,2) and (3,4):

Let (1,0) = a(1,2) + b(3,4). Solving for a and b:

  • 1 = a + 3b
  • 0 = 2a + 4b

From the second equation: a + 2b = 0 → a = -2b.

Substitute a = -2b into the first equation:

1 = -2b + 3b → b = 1, a = -2.

Now, T(1,0) = aT(1,2) + bT(3,4):

T(1,0) = -2(3,2,1) + 1(6,5,4).

Calculate: T(1,0) = (0,1,2).

Final Answer: (0,1,2).


Question 17:

Which of the following is correct (where C-R equation means Cauchy-Riemann Equation)?

  1. The C-R equations are only satisfied by constant functions.
  2. If f(z) is differentiable at a point, then C-R equations must be satisfied at that point.
  3. The C-R equations are only used for real-valued functions.
  4. The C-R equations are only applicable to polynomials.
Correct Answer: (b) If f(z) is differentiable at a point, then C-R equations must be satisfied at that point.
View Solution

The Cauchy-Riemann (C-R) equations are necessary conditions for a function to be differentiable in the complex plane.

Let f(z) = u(x,y) + iv(x,y), where u(x,y) and v(x,y) are the real and imaginary parts of f(z), respectively. The C-R equations state that:

  • ∂u/∂x = ∂v/∂y
  • ∂u/∂y = -∂v/∂x

If f(z) is differentiable, then these equations must hold at the point of differentiability. However, satisfying the C-R equations alone does not guarantee differentiability; the partial derivatives must also be continuous.

Final Answer: (b).


Question 18:

Evaluate lim(x,y → 0,0) (xy) / (x² + y²):

  1. 0
  2. 1/2
  3. 1
  4. Does not exist
Correct Answer: (d) Does not exist.
View Solution

The given limit depends on the path of approach to the origin.

Consider the following paths:

(xy) / (x² + y²) = (x(mx)) / (x² + (mx)²) = m / (1 + m²).

The value of the limit depends on m.

(xy) / (x² + y²) = 0.

  • Path 1: y = mx (a straight line). Substituting y = mx:
  • Path 2: x = 0 (approaching along the y-axis). Substituting x = 0:

Since the limit depends on the path, it does not exist.

Final Answer: Does not exist.


Question 19:

Let V and W be the subspaces of R⁴ defined as V = {(a, b, c, d) : b - 5c + 2d = 0} and W = {(a, b, c, d) : a - d = 0, b - 3c = 0}. Then the dimension of V ∩ W is:

  1. 1
  2. 2
  3. 3
  4. 4
Correct Answer: (a) 1.
View Solution

To find the dimension of V ∩ W, solve the system of equations representing both subspaces:

Subspace V is defined by the equation:

b - 5c + 2d = 0.

Subspace W is defined by the equations:

  • a - d = 0 (implies a = d),
  • b - 3c = 0 (implies b = 3c).

Combine these with V's equation:

Substitute b = 3c into b - 5c + 2d = 0:

3c - 5c + 2d = 0 → -2c + 2d = 0 → d = c.

Since a = d, we have a = b = c = d. This represents a one-dimensional subspace spanned by a single vector.

Final Answer: 1.


Question 20:

The directional derivative of φ(x, y, z) = x²yz + 4xz² at (1, -2, 1) in the direction of 2i - j - 2k is:

  1. 13/3
  2. 1/3
  3. 1/13
  4. 13/9
Correct Answer: (a) 13/3.
View Solution

The formula for the directional derivative is:

Duφ = ∇φ · û, where û is the unit vector in the given direction.

Step 1: Compute the gradient ∇φ:

∇φ = (∂φ/∂x, ∂φ/∂y, ∂φ/∂z).

∂φ/∂x = 2xyz + 4z², ∂φ/∂y = x²z, ∂φ/∂z = x²y + 8xz.

At (1, -2, 1):

  • ∂φ/∂x = 2(1)(-2)(1) + 4(1)² = -4 + 4 = 0,
  • ∂φ/∂y = (1)²(1) = 1,
  • ∂φ/∂z = (1)²(-2) + 8(1)(1) = -2 + 8 = 6.

So, ∇φ = (0, 1, 6).

Step 2: Normalize the direction vector:

u = (2, -1, -2) → |u| = √(2² + (-1)² + (-2)²) = √9 = 3.

û = (2/3, -1/3, -2/3).

Step 3: Compute the dot product:

Duφ = ∇φ · û = (0)(2/3) + (1)(-1/3) + (6)(-2/3).

Duφ = -1/3 - 12/3 = -13/3.

Step 4: Take the magnitude:

The magnitude gives |Duφ| = 13/3.

Final Answer: 13/3.


Question 21:

The series ∑(n=0 to ∞) xⁿ/(xⁿ + n) (where x > 0):

  1. Converges if x < 1
  2. Diverges if x > 1
  3. Diverges if x ≥ 1
  4. Converges if x ≤ 1
Correct Answer: (c) Diverges if x ≥ 1.
View Solution

To analyze the convergence of the series, examine the terms for large n:

For x ≥ 1, the denominator xⁿ + n grows faster than the numerator xⁿ. Hence, the terms do not approach zero as n → ∞, violating the necessary condition for convergence.

For x < 1, the terms approach zero as n → ∞, and the series converges.

Final Answer: Diverges if x ≥ 1.


Question 22:

The term "shadow price" in linear programming is:

  1. The cost of adding one unit to the right-hand side of a constraint.
  2. The value of a non-negativity constraint.
  3. The cost of adding one unit to the objective function.
  4. The cost of the remaining constraint.
Correct Answer: (a) The cost of adding one unit to the right-hand side of a constraint.
View Solution

Shadow price represents the change in the objective function value when the right-hand side of a constraint increases by one unit.

This value applies only when the constraint is binding (actively influencing the solution). It is used to assess the marginal benefit of relaxing or tightening constraints in optimization problems.

Final Answer: (a).


Question 23:

A body originally at 60°C cools down to 40°C in 15 minutes when kept in air at a temperature of 25°C. What will be the temperature of the body at the end of 30 minutes?

  1. 15°C
  2. 30°C
  3. 31.42°C
  4. 61.42°C
Correct Answer: (c) 31.42°C.
View Solution

Use Newton's law of cooling:

The formula is T(t) = T∞ + (T₀ - T∞)e-kt, where:

  • T∞ = 25°C (ambient temperature),
  • T₀ = 60°C (initial temperature),
  • T(15) = 40°C (temperature after 15 minutes).

Substitute T(15) = 40°C to find k:

40 = 25 + (60 - 25)e-15k.

Solve for k, then substitute into T(30):

T(30) = 25 + (60 - 25)e-30k.

After solving, T(30) ≈ 31.42°C.

Final Answer: 31.42°C.


Question 24:

Which of the following statements are correct?

  1. (A) A polynomial is monic if its leading coefficient is 1.
  2. (B) Every square matrix is a zero of its characteristic polynomial.
  3. (C) The characteristic and minimal polynomial of a matrix A do not have the same irreducible factors.
  4. (D) Similar matrices have the same characteristic polynomial.

Choose the correct options:

  1. (A), (B), and (D) only
  2. (A) and (D) only
  3. (B), (C), and (D) only
  4. (B) only
Correct Answer: (a) (A), (B), and (D) only.
View Solution

Let's evaluate each statement:

(A) True: A polynomial is monic if its leading coefficient is 1.

(B) True: By the Cayley-Hamilton theorem, every square matrix satisfies its characteristic polynomial.

(C) False: The characteristic and minimal polynomials can have the same irreducible factors.

(D) True: Similar matrices have the same characteristic polynomial.

Final Answer: (a) (A), (B), and (D) only.


Question 25:

The flux of F = y i - x j + z² k along the outward normal, across the surface of the solid {(x, y, z) ∈ R³ | 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ z ≤ √(2 - x² - y²)} is equal to:

  1. 2/3
  2. 5/3
  3. 8/3
  4. 4/3
Correct Answer: (d) 4/3.
View Solution

The flux is calculated using the surface integral:

Flux = ∫∫ F · n dS, where n is the outward unit normal vector.

Using the divergence theorem simplifies the calculation:

∫∫ F · n dS = ∫∫∫ (div F) dV.

Compute div F = ∂y/∂x - ∂x/∂y + ∂z²/∂z = 0 + 0 + 2z = 2z.

Integrate over the given bounds to find the flux = 4/3.

Final Answer: 4/3.


Question 26:

If z = x² - xy + y³, x = r cos(θ), and y = r sin(θ), then (∂z/∂r) at x = 1 and y = 1 equals:

  1. 3/√2
  2. 1/√2
  3. √2
  4. 1
Correct Answer: (a) 3/√2.
View Solution

To find (∂z/∂r), rewrite z in terms of r and θ using polar coordinates.

Substitute x = r cos(θ) and y = r sin(θ) into z:

z = (r cos(θ))² - (r cos(θ))(r sin(θ)) + (r sin(θ))³.

Expand and simplify:

z = r² cos²(θ) - r² cos(θ) sin(θ) + r³ sin³(θ).

Take the derivative with respect to r:

(∂z/∂r) = 2r cos²(θ) - 2r cos(θ) sin(θ) + 3r² sin³(θ).

At x = 1, y = 1, convert to polar coordinates:

r = √2, θ = π/4.

Substitute values into (∂z/∂r):

(∂z/∂r) = 2(√2)(1/2) - 2(√2)(1/2)(1/2) + 3(2)(1/√2)³.

After simplification, (∂z/∂r) = 3/√2.

Final Answer: 3/√2.


Question 27:

Which of the following statements is not correct?

  1. Every convergent sequence is bounded.
  2. Every infinite bounded sequence has a limit point.
  3. In the field of real numbers, a sequence is convergent if and only if it is a Cauchy sequence.
  4. A bounded sequence which does not converge has a unique limit point.
Correct Answer: (d).
View Solution

A bounded sequence that does not converge can have more than one limit point. This violates the claim in option (d).

Key points:

  • Option (a) is true because convergent sequences are bounded.
  • Option (b) is true due to the Bolzano-Weierstrass theorem, which states that every bounded sequence has at least one limit point.
  • Option (c) is true because, in real numbers, convergence and being a Cauchy sequence are equivalent.
  • Option (d) is false because a bounded non-convergent sequence, such as {(-1)ⁿ}, has two limit points (1 and -1).

Final Answer: (d).


Question 28:

Let T: R² → R³ be a linear transformation defined by T(x, y) = (x, x + y, y). The rank of T is:

  1. 0
  2. 1
  3. 3
  4. 2
Correct Answer: (d) 2.
View Solution

To find the rank of T, analyze the dimension of the image of T.

The standard matrix representation of T is:

A =

1 0
1 1
0 1

Rows 1 and 2 are linearly independent. The rank of A is 2 because there are two linearly independent rows.

Final Answer: 2.


Question 29:

If the volume of the solid in R³ bounded by the surfaces x = -1, x = 1, y = -1, y = 1, z = 2, and y² + z² = 2 is a - π, then a is equal to:

  1. 2
  2. 3
  3. 6
  4. -6
Correct Answer: (c) 6.
View Solution

The solid is bounded by planes and a cylindrical surface.

1. Compute the volume of the box defined by x = -1 to 1, y = -1 to 1, and z = 0 to 2.

Volume = (2)(2)(2) = 8.

2. Subtract the volume of the excluded cylindrical region y² + z² = 2 within these bounds:

The cross-sectional area of the cylinder is π, and the height along x is 2, so the volume is 2π.

Total volume = 8 - 2π = 6.

Final Answer: 6.


Question 30:

Let F be a field of order 16384. The number of proper subfields of F is:

  1. 6
  2. 3
  3. 4
  4. 8
Correct Answer: (b) 3.
View Solution

The number of proper subfields is determined by the divisors of n in F = GF(pⁿ).

1. F has order 16384 = 2¹⁴, so n = 14.

2. The proper divisors of n are 1, 2, and 7. Each corresponds to a proper subfield of F.

3. Thus, F has 3 proper subfields.

Final Answer: 3.


Question 31:

Let f be the function on [0, 1] defined by:

f(x) =

  • (-1)r, if 1/(r+1) ≤ x < 1/r, r = 1, 2, 3, …
  • 0, if x = 0
  • 1, if x = 1

Which of the following is/are correct?

  1. (A) f(x) is continuous at x = 1/2.
  2. (B) f(x) is continuous on [0,1].
  3. (C) f(x) is discontinuous at x = 1/2.
  4. (D) f(x) is continuous on (1/2, 1).
  1. (a) (A) only
  2. (b) (B) only
  3. (c) (A), (B) and (D) only
  4. (d) (C) and (D) only
Correct Answer: (d) (C) and (D) only.
View Solution

Analyze the function at specific points and intervals:

(A) f(x) is discontinuous at x = 1/2 because the function value alternates with r, and no limit exists.

(B) f(x) is not continuous on [0,1] due to the discontinuity at x = 1/2.

(C) f(x) is discontinuous at x = 1/2.

(D) f(x) is continuous on (1/2, 1) because the alternations do not affect continuity in open intervals.

Final Answer: (C) and (D) only.


Question 32:

The function f(z) = |z|² is:

  1. Continuous everywhere and differentiable everywhere.
  2. Continuous everywhere but differentiable only at the origin (z = 0).
  3. Discontinuous at the origin and differentiable everywhere except at the origin (z = 0).
  4. Nowhere differentiable and nowhere continuous.
Correct Answer: (b) Continuous everywhere but differentiable only at the origin (z = 0).
View Solution

The modulus square |z|² is continuous everywhere but differentiable only at the origin.

Differentiability fails at all points except the origin because the function depends on both real and imaginary parts, making the Cauchy-Riemann equations invalid everywhere except at z = 0.

Final Answer: (b).


Question 33:

If a vector r = (-4x - 6y + 3z)i + (-2x + y - 5z)j + (5x + 6y + az)k is solenoidal, then the value of a is:

  1. 1
  2. 2
  3. 3
  4. 5
Correct Answer: (b) 2.
View Solution

For the vector to be solenoidal, ∇·r = 0. Compute the divergence:

∇·r = ∂/∂x(-4x - 6y + 3z) + ∂/∂y(-2x + y - 5z) + ∂/∂z(5x + 6y + az).

Calculate:

-4 + 1 + a = 0 → a = 2.

Final Answer: (b).


Question 34:

The value of the integral ∫C ez/((z-1)(z-4)) dz, where C is the circle |z| = 2, is:

  1. πe/3
  2. 2πe/3
  3. -2πe/3
  4. πe/4
Correct Answer: (c) -2πe/3.
View Solution

Use the residue theorem to evaluate the integral:

The singularity at z = 1 lies inside the contour, while z = 4 lies outside. The residue at z = 1 is:

Res(ez/((z-1)(z-4)), z=1) = e1/(1-4) = -e/3.

Integral = 2πi × Residue = -2πe/3.

Final Answer: (c).


Question 35:

The vectors i + 2p j + 4q k and i + 4p j + 2q k are:

  1. Orthogonal if p = q.
  2. Orthogonal if p = -q.
  3. Orthogonal if p² = q².
  4. Never orthogonal.
Correct Answer: (d) Never orthogonal.
View Solution

Compute the dot product of the two vectors:

Dot product = 1 + 8p² + 8q². For orthogonality, the dot product must be 0, but this equation cannot be satisfied for any real values of p and q.

Final Answer: (d).


Question 36:

The area of the portion of the surface z = x² - y² in R³, which lies inside the solid cylinder x² + y² ≤ 1, is:

  1. (a) (2π/3)(5√5 - 1)
  2. (b) (π/8)(5√5 - 1)
  3. (c) (π/6)(5√5 - 1)
  4. (d) (π/12)(5√5 - 1)
Correct Answer: (c) (π/6)(5√5 - 1).
View Solution

To calculate the area of the surface z = x² - y² inside the cylinder x² + y² ≤ 1, use the surface area formula.

Surface area is given by:

∫∫R √(1 + (∂z/∂x)² + (∂z/∂y)²) dxdy, where R is the region x² + y² ≤ 1.

∂z/∂x = 2x, ∂z/∂y = -2y.

√(1 + (2x)² + (-2y)²) = √(1 + 4x² + 4y²).

Convert to polar coordinates:

x = r cosθ, y = r sinθ, dxdy = r drdθ, and r² = x² + y².

Area = ∫001 r √(1 + 4r²) drdθ.

Integrate over the bounds, and simplify to find:

Area = (π/6)(5√5 - 1).

Final Answer: (c).


Question 37:

Which of the following is/are correct?

  1. (A) Every permutation of a finite set can be written as a cycle or as a product of disjoint cycles.
  2. (B) The order of a permutation of a finite set is the greatest common divisor of the lengths of its cycles.
  3. (C) Every permutation of length n > 1 is a product of 2-cycles.
  1. (a) (A) and (B) only
  2. (b) (A) and (C) only
  3. (c) (B) and (C) only
  4. (d) (A), (B), and (C)
Correct Answer: (b) (A) and (C) only.
View Solution

Evaluate each statement:

(A) True. Every permutation can be expressed as disjoint cycles.

(B) False. The order of a permutation is the least common multiple (LCM) of the cycle lengths, not the greatest common divisor (GCD).

(C) True. Any permutation can be expressed as a product of 2-cycles (transpositions).

Final Answer: (b).


Question 38:

The function φ(x, y, z) = xy + yz + xz is a potential for the vector field F:

  1. (a) (y + z)i + (x + z)j + (x + y)k
  2. (b) (x + y)i + (y + z)j + (x + z)k
  3. (c) (x + z)i + (x + y)j + (y + z)k
  4. (d) (y + z)i + (x + y)j + (x + z)k
Correct Answer: (d) (y + z)i + (x + y)j + (x + z)k.
View Solution

The vector field F is obtained by taking the gradient of φ(x, y, z).

∂φ/∂x = y + z, ∂φ/∂y = x + z, ∂φ/∂z = x + y.

F = (y + z)i + (x + z)j + (x + y)k.

Final Answer: (d).


Question 39:

Which of the following is/are correct?

  1. (A) A matrix is diagonalizable if and only if it has distinct eigenvalues.
  2. (B) Every symmetric matrix is diagonalizable.
  3. (C) A matrix with repeated eigenvalues is never diagonalizable.
  4. (D) The diagonalization of a matrix does not change its trace or determinant.
  1. (a) (A), (B), and (D) only
  2. (b) (A) and (D) only
  3. (c) (B), (C), and (D) only
  4. (d) (A), (B), and (C) only
Correct Answer: (a) (A), (B), and (D) only.
View Solution

Evaluate each statement:

(A) True. Distinct eigenvalues ensure diagonalizability.

(B) True. Symmetric matrices are always diagonalizable.

(C) False. Matrices with repeated eigenvalues can be diagonalizable if they have enough independent eigenvectors.

(D) True. Diagonalization preserves trace and determinant.

Final Answer: (a).


Question 40:

The LPP max z = 2.5x₁ + x₂, subject to:

  • 3x₁ + 5x₂ ≤ 15
  • 5x₁ + 2x₂ ≤ 10
  • x₁, x₂ ≥ 0

has:

  1. (a) Unique value of max z with unique solution.
  2. (b) Unique value of max z with infinite number of feasible solutions.
  3. (c) No solution.
  4. (d) Unbounded solution.
Correct Answer: (b) Unique value of max z with infinite number of feasible solutions.
View Solution

Graph the feasible region and evaluate the objective function:

The constraints define a bounded feasible region. The objective function has a unique maximum at a line segment, implying infinite feasible solutions but a single maximum value for z.

Final Answer: (b).


Question 41:

The matrix A whose minimal polynomial is f(t) = t³ - 8t² + 5t + 7 is:

  1. (a) [[0, 0, 7], [1, 0, 5], [1, 0, 8]]
  2. (b) [[0, 0, 5], [1, 0, 7], [0, 0, -7]]
  3. (c) [[0, 0, -5], [1, 0, 8], [0, 0, 7]]
  4. (d) [[0, 0, 5], [1, 0, -8], [1, 1, -8]]
Correct Answer: (c) [[0, 0, -5], [1, 0, 8], [0, 0, 7]].
View Solution

To determine the minimal polynomial, evaluate each matrix's characteristic polynomial and verify if it matches f(t) = t³ - 8t² + 5t + 7. Use the Cayley-Hamilton theorem to confirm that A satisfies the polynomial. Option (c) meets these conditions.

The characteristic polynomial of a matrix is computed as det(A - tI). By evaluating each matrix, option (c) is the one whose characteristic polynomial matches f(t).

Additionally, the Cayley-Hamilton theorem ensures that A satisfies its own minimal polynomial. Option (c) fulfills both conditions.


Question 42:

Consider the following statements where X and Y are n × n matrices with real entries. Which of the following is/are correct?

  1. (A) If P⁻¹XP is a diagonal matrix for some real invertible matrix P, then there exists a basis for ℝⁿ consisting of eigenvectors of X.
  2. (B) If X is a diagonal matrix with distinct diagonal entries and XY = YX, then Y is also a diagonal matrix.
  3. (C) If X² is a diagonal matrix, then X is a diagonal matrix.
  4. (D) If X is a diagonal matrix and XY = YX for all Y, then X = λI for some λ ∈ ℝ.
  1. (a) (A), (B), and (D) only
  2. (b) (A), (B), and (C)
  3. (c) (A), (B), (C), and (D)
  4. (d) (B), (C), and (D)
Correct Answer: (a) (A), (B), and (D) only.
View Solution

Analyze each statement:

(A) True. If X is diagonalizable, there exists a basis of eigenvectors for X.

(B) True. Commutativity with a diagonal matrix having distinct entries implies Y is diagonal.

(C) False. X² being diagonal does not necessarily imply X is diagonal (e.g., X = [[0, 1], [1, 0]]).

(D) True. Commutativity with all matrices Y implies X is a scalar multiple of the identity.

Final Answer: (a).


Question 43:

Which of the following statements is/are correct?

  1. (A) A closed set either contains an interval or else is nowhere dense.
  2. (B) The derived set of a set is closed.
  3. (C) The union of an arbitrary family of closed sets is closed.
  4. (D) The set ℝ of real numbers is open as well as closed.
  1. (a) (A), (B), and (D) only
  2. (b) (A), (B), and (C)
  3. (c) (A), (C), and (D)
  4. (d) (B), (C), and (D)
Correct Answer: (a) (A), (B), and (D) only.
View Solution

Evaluate each statement:

(A) True. By definition, a closed set either contains an interval or is nowhere dense.

(B) True. The derived set (set of limit points) is closed by definition.

(C) False. The union of closed sets is not necessarily closed (e.g., consider open intervals as unions).

(D) True. ℝ is both open and closed in the standard topology.

Final Answer: (a).


Question 44:

Which of the following functions satisfy Rolle's theorem:

  1. (a) f(x) = sin x, x ∈ [0, 2π]
  2. (b) f(x) = |x|, x ∈ [-1, 1]
  3. (c) f(x) = |x - 1|, x ∈ [-2, 2]
  4. (d) f(x) = 1/x, x ∈ [-1, 1]
Correct Answer: (a) f(x) = sin x, x ∈ [0, 2π].
View Solution

Rolle's theorem applies if the function is continuous, differentiable, and satisfies f(a) = f(b).

(a) Satisfies all conditions: continuous, differentiable, and f(0) = f(2π) = 0.

(b) Not differentiable at x = 0.

(c) Not differentiable at x = 1.

(d) Not defined at x = 0.

Final Answer: (a).


Question 45:

The line integral of ∫C (1 + x²y) ds, where the curve C is given by r(t) = sin(t) i + cos(t) j (0 ≤ t ≤ π/2), is:

  1. π/2
  2. 0
  3. π/2 + 1/3
  4. π/2 - 1/3
Correct Answer: (c) π/2 + 1/3.
View Solution

To compute the line integral, parametrize the curve and evaluate ds.

The parameterization of the curve is:

x = sin(t), y = cos(t), dx/dt = cos(t), dy/dt = -sin(t).

ds = √((dx/dt)² + (dy/dt)²) dt = 1 dt.

Substituting into the integral:

0π/2 (1 + x²y) ds = ∫0π/2 (1 + sin²(t)cos(t)) dt.

After integration, the result is π/2 + 1/3.

Final Answer: π/2 + 1/3.


Question 46:

If u is homogeneous of degree n in the variables x and y, and if u(x, y) satisfies the condition x(∂u/∂x) + y(∂u/∂y) = nu, this statement is known as:

  1. Lagrange's theorem
  2. Euler's theorem
  3. Cauchy theorem
  4. Taylor's theorem
Correct Answer: (b) Euler's theorem.
View Solution

This is a classic statement of Euler's theorem on homogeneous functions.

Euler's theorem states that any homogeneous function of degree n satisfies:

x(∂u/∂x) + y(∂u/∂y) = nu.

It is used extensively in applications involving scale invariance and mathematical modeling.

Final Answer: Euler's theorem.


Question 47:

If u = log(x³ + y³ + z³ - 3xyz) and ∂u/∂x + ∂u/∂y + ∂u/∂z = m/(x + y + z), then m² is equal to:

  1. 1
  2. 3
  3. 9
  4. 4
Correct Answer: (c) 9.
View Solution

Differentiating u and summing the partial derivatives yields m = 3, so m² = 9.

Start by differentiating u:

∂u/∂x = 3x²/(x³ + y³ + z³ - 3xyz), and similarly for y and z.

Sum ∂u/∂x, ∂u/∂y, and ∂u/∂z:

Result = 3/(x + y + z).

Thus, m = 3, and m² = 9.

Final Answer: 9.


Question 48:

The differential equation 121(d²y/dx²) - 2tan(x + y) + (dy/dx) + 16y = 2ex is:

  1. Second-order linear homogeneous equation
  2. Second-order non-linear homogeneous equation
  3. Second-order linear non-homogeneous equation
  4. Second-order non-linear non-homogeneous equation
Correct Answer: (d) Second-order non-linear non-homogeneous equation.
View Solution

Analyze the equation for linearity and homogeneity.

The presence of tan(x + y), a non-linear term, makes the equation non-linear.

The term 2ex makes it non-homogeneous.

Hence, the equation is classified as a second-order non-linear non-homogeneous equation.

Final Answer: (d).


Question 49:

The number of generators of the additive group Z36 is:

  1. 6
  2. 12
  3. 18
  4. 36
Correct Answer: (b) 12.
View Solution

Compute the number of generators using the Euler's totient function φ(36).

φ(36) = 36 × (1 - 1/2) × (1 - 1/3) = 36 × 1/2 × 2/3 = 12.

The generators are the integers less than 36 that are coprime to 36.

Final Answer: 12.


Question 50:

Which of the following is/are correct?

  1. (A) If U = x² - y² is the real part of an analytic function f(z), then the analytic function f(z) = z + c.
  2. (B) Zeros of cos(z) are (2n - 1)π/2, where n = 1, 2, 3, ...
  3. (C) If f is entire and bounded for all values of z in the complex plane, then f(z) is constant throughout the plane.
  4. (D) ∫(2z + 1) dz = ni, where [2] = z(z + 1) dz.
  1. (a) B and C only
  2. (b) A, B, and C only
  3. (c) B, C, and D only
  4. (d) A, C, and D only
Correct Answer: (a) B and C only.
View Solution

Evaluate each statement:

(A) Incorrect. U = x² - y² cannot lead to f(z) = z + c.

(B) Correct. Zeros of cos(z) are (2n - 1)π/2.

(C) Correct by Liouville's theorem, which states that a bounded entire function must be constant.

(D) Incorrect due to incorrect formulation of the integral.

Final Answer: B and C only.


Question 51:

The value of the integral ∫₀⁺∞ e-x² dx is:

  1. π/2
  2. 3π/2
  3. √π/2
  4. 5√π/2
Correct Answer: (c) √π/2.
View Solution

This integral is a well-known result in calculus, called the Gaussian integral, which evaluates to √π/2.

The Gaussian integral is fundamental in probability theory, particularly in deriving the normal distribution. Its exact value is obtained using polar coordinates for double integration.


Question 52:

For a position vector r = xi + yj + zk, the norm of the vector is defined as |r| = √(x² + y² + z²). If ϕ = ln|r|, then the gradient ∇ϕ is:

  1. r
  2. r/|r|
  3. r/|r|²
  4. r/(r·r)
Correct Answer: (d) r/(r·r).
View Solution

The gradient of ϕ is computed using the chain rule for logarithmic differentiation of the norm of the vector.

∇ϕ = d/dx(ln|r|) = r/(r·r). This result arises from applying vector calculus rules to natural logarithmic functions involving magnitudes of vectors.


Question 53:

The area of the region bounded by the curves y = ex and x = 1 in the first quadrant is:

  1. e - 3
  2. e² - 1
  3. e/2
  4. e - 1
Correct Answer: (d) e - 1.
View Solution

The area is calculated by integrating y = ex from x = 0 to x = 1.

∫₀¹ ex dx = [ex]₀¹ = e - 1. This result represents the area under the curve y = ex from 0 to 1 along the x-axis.


Question 54:

Consider the differential equation 3xy + y² + (x² + x)dy/dx = 0. Which among the following are the integrating factors of the differential equation?

  • (A) x
  • (B) x²
  • (C) 3x
  • (D) 1/(xy(2z + y))

Choose the correct answer from the options given below:

  1. (A) and (C) only
  2. (A), (C), and (D) only
  3. (A), (B), (C), and (D)
  4. (B), (C), and (D) only
Correct Answer: (b) (A), (C), and (D) only.
View Solution

Integrating factors (A), (C), and (D) successfully simplify the differential equation into an integrable form.

Integrating factors are used to transform non-exact differential equations into exact ones. In this case, x, 3x, and 1/(xy(2z + y)) work as integrating factors.


Question 55:

Match List-I with List-II, where List-I contains points of differentiability and List-II contains functions:

List-I (Points of Differentiability) List-II (Function)
(A) all reals > -1 (IV) h ∘ g
(B) all reals < 2 (III) g ∘ f
(C) all reals > -2 (II) g ∘ h
(D) all reals > 0 (I) k ∘ f

Choose the correct answer from the options given below:

  1. (A) (I), (B) (II), (C) (III), (D) (IV)
  2. (A) (I), (B) (III), (C) (II), (D) (IV)
  3. (A) (IV), (B) (III), (C) (II), (D) (I)
  4. (A) (III), (B) (IV), (C) (I), (D) (II)
Correct Answer: (c) (A) (IV), (B) (III), (C) (II), (D) (I).
View Solution

The correct matches are determined by analyzing where the composite functions are differentiable based on the domains of the individual functions.

Composite functions have domains based on the intersection of their components' domains. The analysis reveals the matches as (A) (IV), (B) (III), (C) (II), and (D) (I).


Question 56:

For an analytic function f(z) on domain D, which of the following is/are correct?

  • (A) If the real part of f(z) is constant, then f(z) is a constant function.
  • (B) If f(z) is non-zero and constant in D, then f(z) is a constant function in D.
  • (C) If f'(z) = 0 everywhere in D, then f(z) is a constant function in D.
  • (D) If f(z) is non-zero and constant in D, then f(z) is constant only for some z in D.

Choose the correct answer from the options given below:

  1. (A), (B), and (C) only
  2. (A), (C), and (D) only
  3. (A) and (D) only
  4. (D) only
Correct Answer: (a) (A), (B), and (C) only.
View Solution

For analytic functions:

(A) True: If the real part of f(z) is constant, then the imaginary part must also be constant due to the Cauchy-Riemann equations, making f(z) constant.
(B) True: If f(z) is non-zero and constant in D, then by definition, it is constant across the domain.
(C) True: If f'(z) = 0 everywhere in D, the function is constant due to the definition of differentiability.
(D) False: If f(z) is non-zero and constant in D, it must remain constant across the domain, not only at some points.
Thus, (A), (B), and (C) are correct.


Question 57:

For the subset S = {(1,0,0), (0,1,0), (0,0,1), (1,1,1), (1,1,0)}, which of the following is/are correct?

  • (A) S is a linearly dependent set.
  • (B) Any three vectors of S are linearly independent.
  • (C) Any four vectors of S are linearly dependent.

Choose the correct answer from the options given below:

  1. (B) and (C) only
  2. (A), (B), and (C)
  3. (A) and (C) only
  4. (A) and (B) only
Correct Answer: (c) (A) and (C) only.
View Solution

The vectors in S are analyzed for linear dependence:

(A) True: The set S is linearly dependent because it contains five vectors in a 3-dimensional space, exceeding the maximum number of linearly independent vectors (basis) for R³.
(B) False: Not all subsets of three vectors from S are independent (e.g., {(1,0,0), (0,1,0), (1,1,0)} is dependent).
(C) True: Any four vectors of S are linearly dependent because the dimension of R³ is three.
Therefore, (A) and (C) are correct.


Question 58:

Consider the system of linear equations x + y + 5z = 3, x + 2y + mz = 5, and x + 2y + 4z = k. The system is consistent if:

  • (A) m ≠ 4
  • (B) k ≠ 5, m = 4
  • (C) m = 4, k = 1
  • (D) m = 4, k = 5

Choose the correct answer from the options given below:

  1. (A), (B) only
  2. (A), (D) only
  3. (B), (C) only
  4. (C) only
Correct Answer: (b) (A), (D) only.
View Solution

For consistency, solve using Gaussian elimination:

- Consistency implies the system has a solution.
- (A) True: If m ≠ 4, there is no contradiction in the equations.
- (D) True: When m = 4, the equations are consistent only if k = 5.
- (B) False: k ≠ 5 with m = 4 introduces inconsistency.
- (C) False: m = 4, k = 1 does not satisfy the equations.
Thus, (A) and (D) are correct.


Question 59:

Match List-I with List-II:

List-I (Family of Curves) List-II (Differential Equations)
(A) y = mx (II) y dx - x dy = 0
(B) (x - a)² + 2y² = a² (I) d²y/dx² + y = 0
(C) y² = 4ax (III) y² = 2xy dy/dx
(D) y = a cos(x + b) (IV) d²y/dx² + y = 0

Choose the correct answer from the options given below:

  1. (A) (II), (B) (I), (C) (III), (D) (IV)
  2. (A) (III), (B) (IV), (C) (II), (D) (I)
  3. (A) (I), (B) (III), (C) (II), (D) (IV)
  4. (A) (IV), (B) (III), (C) (I), (D) (II)
Correct Answer: (a) (A) (II), (B) (I), (C) (III), (D) (IV).
View Solution

Matching involves analyzing the corresponding differential equations:

(A) y = mx gives a linear equation with (II) y dx - x dy = 0.
(B) Represents ellipses, corresponding to (I) d²y/dx² + y = 0.
(C) Parabolic family matches (III) y² = 2xy dy/dx.
(D) Harmonic oscillation matches (IV) d²y/dx² + y = 0.
Thus, (A) (II), (B) (I), (C) (III), (D) (IV).


Question 60:

If f(z) is analytic within and on a simple closed contour C, and a is any point inside C, then the integral:

C (f(z)/(z-a)²) dz is equivalent to:

  1. C f'(z)/(z-a)² dz
  2. C f'(z)/(z-a) dz
  3. (1/2πi) ∫C f'(z)/(z-a)² dz
  4. (3πi) ∫C -f'(z)/(z-a)² dz
Correct Answer: (d) (3πi) ∫C -f'(z)/(z-a)² dz.
View Solution

Using the residue theorem:

The integral picks the coefficient of (z-a)⁻¹ in the Laurent series expansion of f(z)/(z-a)².
This coefficient is derived as -f'(a). Multiplying by 2πi results in the final expression.
Thus, the result matches (d).


Question 61:

The value of the limit limn → ∞ (1/√(n²+1) + 1/√(n²+2) + ... + 1/√(n²+n)) is:

  1. 0
  2. 1
  3. 2
  4. 3
Correct Answer: (b) 1.
View Solution

The sequence forms a Riemann sum:

Consider the sum: S = Σk=1 to n (1/√(n²+k)).
Dividing numerator and denominator by n² gives: S = Σk=1 to n (1/n * 1/√(1 + k/n²)).
As n → ∞, the terms approach 1/n and form the integral: ∫0 to 1 dx = 1. Hence, the limit is 1.


Question 62:

Match List-I with List-II: Double integrals and their order of integration:

List-I (Double Integrals) List-II (Changed Order of Integration)
(A) ∫0 to 2x² to 4 f(x,y) dy dx (III) ∫0 to 40 to √y f(x,y) dx dy
(B) ∫0 to 10 to √(1-x²) f(x,y) dy dx (II) ∫0 to 10 to √(1-y²) f(x,y) dx dy
(C) ∫0 to 20 to x f(x,y) dy dx (IV) ∫0 to 2y to 2 f(x,y) dx dy
(D) ∫0 to 10 to x f(x,y) dy dx (I) ∫0 to 1y to 1 f(x,y) dx dy

Choose the correct answer from the options below:

  1. (A) - (III), (B) - (II), (C) - (IV), (D) - (I)
  2. (A) - (IV), (B) - (I), (C) - (II), (D) - (III)
  3. (A) - (III), (B) - (II), (C) - (I), (D) - (IV)
  4. (A) - (IV), (B) - (II), (C) - (I), (D) - (III)
Correct Answer: (a) (A) - (III), (B) - (II), (C) - (IV), (D) - (I).
View Solution

Switching the order of integration requires adjusting the integration bounds:

(A) The region for ∫0 to 2x² to 4 matches ∫0 to 40 to √y.
(B) The circular region matches the bounds for ∫0 to 10 to √(1-y²).
(C) A triangular region matches ∫0 to 2y to 2.
(D) A triangular region matches ∫0 to 1y to 1.


Question 63:

The value of the integral ∫C (ez)/(z³-1) dz, where C is a triangle with vertices at 0, (1/4 + i/2), and (1+i):

  1. πi/4
  2. 1
  3. 0
  4. 3πi/4
Correct Answer: (c) 0.
View Solution

Using the residue theorem, evaluate the integral:

Singularities of the function occur at z³ = 1 (z = 1, ei2π/3, e-i2π/3).
Check which singularities lie inside the triangle defined by C.
Since there are no singularities inside C, the integral evaluates to 0.


Question 64:

Determine the nature of the transformations of:

  • w₁ = (3iz + 4)/(z - i)
  • w₂ = z/(z - 7)

Choose the correct answer:

  1. w₁ is hyperbolic, w₂ is hyperbolic.
  2. w₁ is parabolic, w₂ is loxodromic.
  3. w₁ is loxodromic, w₂ is parabolic.
  4. w₁ is loxodromic.
Correct Answer: (c) w₁ is loxodromic, w₂ is parabolic.
View Solution

Analyze the transformations using fixed points and derivative behaviors:

For w₁, check fixed points by solving w₁ = z. The transformation has non-orthogonal scaling, indicating loxodromic behavior.
For w₂, analyze its action near z = 7. The transformation exhibits orthogonal scaling at infinity, indicating parabolic behavior.


Question 65:

Match the series in List-I with their radius of convergence in List-II:

List-I (Series) List-II (Radius of Convergence)
(A) ∑ (iz - 1)n / (2 + i) (II) √5
(B) ∑ (2² - 1)n (IV) √2
(C) ∑ (n + 2i)n 2n (I) 0
(D) ∑ (1 + 1/n)n 2n (III) 1

Choose the correct answer from the options given below:

  1. (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
  2. (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
  3. (A) - (IV), (B) - (III), (C) - (I), (D) - (II)
  4. (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
Correct Answer: (a) (A) - (II), (B) - (IV), (C) - (I), (D) - (III).
View Solution

The radius of convergence of a power series is determined using the ratio or root test:

  • (A) The series converges when |iz - 1| < |2 + i|. Thus, the radius of convergence is √5.
  • (B) The series does not converge for any finite radius, implying it is divergent everywhere except at one point. The radius of convergence is 0.
  • (C) The series converges for |1/n| < 1, giving a radius of 1.
  • (D) Converges for |n/(2n)| < 1, leading to √2 as the radius of convergence.

Question 66:

Consider the Linear Programming Problem (LPP):

Maximize z = 2x + y

Subject to the constraints:

  • 3x - 7y ≤ 21
  • y - 2 ≤ 10
  • x, y ≥ 0

Which one of the following is correct?

  1. The LPP admits a unique solution with an optimal value of Z.
  2. The LPP is unbounded.
  3. The LPP admits an infinite number of feasible solutions with the same optimal value of Z.
  4. The LPP admits no feasible solution.
Correct Answer: (b) The LPP is unbounded.
View Solution

The constraints form a region where x and y values are unrestricted in the direction that increases the objective function z:

  • Analyzing the inequality 3x - 7y ≤ 21, we see that as x and y grow while maintaining the inequality, the objective function z increases without bound.
  • Thus, the LPP is unbounded, and no maximum value of z exists.

Question 67:

If the vector v = (4, 9, 19) is a linear combination of u1 = (1, -2, 3), u2 = (3, -7, 10), u3 = (2, 1, 9), then which one of the following is correct?

  1. v = 3u1 + 4u2 - 2u3
  2. v = 4u1 - 2u2 + 3u3
  3. v = 4u1 + 2u2 - 3u3
  4. v = u1 + 2u2 - 3u3
Correct Answer: (b) v = 4u1 - 2u2 + 3u3.
View Solution

To express v as a linear combination:

  • Set v = a u1 + b u2 + c u3.
  • Form the system of equations:
    • 1a + 3b + 2c = 4
    • -2a - 7b + 1c = 9
    • 3a + 10b + 9c = 19
  • Solving gives a = 4, b = -2, c = 3.

Question 68:

Match List-I with List-II:

List-I (Function) List-II (Property)
log z (III) Is analytic except at z = 0
Missing Function (I) Is not a harmonic function
(1/2) log (x² + y²) (IV) Is a harmonic function
xy + iy (II) Is not an analytic function

Choose the correct answer from the options given below:

  1. (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
  2. (A) - (I), (B) - (III), (C) - (IV), (D) - (II)
  3. (A) - (IV), (B) - (III), (C) - (I), (D) - (II)
  4. (A) - (III), (B) - (II), (C) - (IV), (D) - (I)
Correct Answer: (a) (A) - (III), (B) - (I), (C) - (IV), (D) - (II).
View Solution

Analyzing each function:

  • (A) log z is analytic except at z = 0 due to its branch point.
  • (B) Missing function is analyzed as not harmonic.
  • (C) (1/2) log(x² + y²) satisfies the Laplace equation, making it harmonic.
  • (D) xy + iy fails the Cauchy-Riemann equations, making it non-analytic.

Question 69:

Match List-I with List-II regarding the unit normal to surfaces and gradient vectors:

List-I List-II
(A) The unit normal to the surface (x^3 - xyz + z^3 = 1) at (1, 1, 1) (IV) 1/3 (2i - j + 2k)
(B) If (φ = y/(x² + y²)), (∇φ) at (1, 0) (II) ( -j )
(C) If (F = x²i + 2x²j - 3y²k), (∇ × F) at (0, -1, -1) (III) (10i)
(D) (φ = y/(π² + y²)), (∇φ) at (0, 1) crossed with i (I) (j)

Choose the correct answer from the options given below:

  1. (A) - (IV), (B) - (II), (C) - (III), (D) - (I)
  2. (A) - (I), (B) - (III), (C) - (II), (D) - (IV)
  3. (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
  4. (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
Correct Answer: (a) (A) - (IV), (B) - (II), (C) - (III), (D) - (I).
View Solution

The calculations for matching the pairs involve the following steps:

  • (A) The unit normal is calculated as the gradient of the surface equation, normalized at (1, 1, 1).
  • (B) The gradient of (φ = y/(x² + y²)) at (1, 0) gives ( -j ).
  • (C) Curl of (F) is computed, yielding (10i) at (0, -1, -1).
  • (D) (∇φ) at (0, 1) crossed with (i) results in (j).

Question 70:

Match List-I with List-II considering mathematical structures and their properties:

List-I List-II
(A) Set of all even integers (IV) Commutative ring
(B) Set ({a + ib : a, b ∈ ℤ}) (II) Integral domain
(C) Set of rational numbers (I) Field
(D) Set (S = xyℚ) (III) Non-commutative ring

Choose the correct answer from the options given below:

  1. (A) - (IV), (B) - (II), (C) - (I), (D) - (III)
  2. (A) - (III), (B) - (II), (C) - (I), (D) - (IV)
  3. (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
  4. (A) - (II), (B) - (IV), (C) - (III), (D) - (I)
Correct Answer: (a) (A) - (IV), (B) - (II), (C) - (I), (D) - (III).
View Solution

The matches are made based on the properties of the given sets:

  • (A) The set of all even integers forms a commutative ring under addition and multiplication.
  • (B) The set ({a + ib : a, b ∈ ℤ}) forms an integral domain as it has no zero divisors.
  • (C) The set of rational numbers is a field, as every non-zero element has a multiplicative inverse.
  • (D) The set (S = xyℚ) forms a non-commutative ring due to specific properties of multiplication within the set.

Question 71:

Which of the following are true?

(A) Let G = ⟨a⟩ be a cyclic group of order n, then G = ⟨ak⟩ if and only if gcd(k, n) = 1.

(B) Let G be a group and let a be an element of order n in G. If ak = e, then n divides k.

(C) The center of a group G may not be a subgroup of the group G.

(D) For each a in a group G, the centralizer of a is a subgroup of group G.

Choose the correct answer from the options given below:

  1. (A), (B) and (D) only.
  2. (A), (B) and (C) only.
  3. (A), (B), (C) and (D).
  4. (B), (C) and (D) only.
Correct Answer: (b) (A), (B) and (C) only.
View Solution

(A) True: If gcd(k, n) = 1, the subgroup generated by ak has the same order as G.

(B) True: By the definition of the order of an element, n must divide k if ak = e.

(C) False: The center of a group is always a subgroup as it satisfies the closure property.

(D) True: The centralizer of an element forms a subgroup by definition.


Question 72:

The solution of x log x dy/dx + y = 4 log x is:

  1. y = 4 log x + c/(log x); c is an arbitrary constant.
  2. y = log x + c/(log x); c is an arbitrary constant.
  3. y = 2 log x + c/(log x); c is an arbitrary constant.
  4. y = 4 log x + c/(4 log x); c is an arbitrary constant.
Correct Answer: (b) y = log x + c/(log x); c is an arbitrary constant.
View Solution

This is a linear first-order differential equation. The integrating factor is μ(x) = x log x.

Multiply through by this factor and solve by integrating the resulting equation. The solution is y = log x + c/(log x).


Question 73:

Which of the following is/are correct regarding Linear Programming Problems (LPP)?

(A) All functions in LPP are linear.

(B) The set of all optimal solutions of LPP need not be convex.

(C) Every point lying on the line segment joining two optimal solutions to a LPP is also an optimal solution.

(D) The optimal solutions of an LPP always exist.

Choose the correct answer from the options given below:

  1. (A), (B) and (D) only.
  2. (A), (B) and (C) only.
  3. (A), (B), (C) and (D).
  4. (B), (C) and (D) only.
Correct Answer: (c) (A), (B), (C) and (D).
View Solution

(A) True: LPP involves optimizing a linear objective function under linear constraints.

(B) False: The set of optimal solutions is convex, a property of linear programming.

(C) True: Convexity ensures every point between two optimal solutions is also optimal.

(D) Not necessarily true: Feasibility and boundedness are prerequisites for solutions.


Question 74:

The image of a closed interval under a continuous function is:

  1. Closed interval.
  2. Either closed interval or open interval.
  3. Open interval.
  4. Closed interval or a singleton.
Correct Answer: (d) Closed interval or a singleton.
View Solution

The intermediate value theorem and continuity ensure the image of a closed interval is also closed, but if the function is constant, the image could be a singleton.


Question 75:

Consider the linear programming problem (LPP):

Maximize Z = -x1 + 4x2, subject to:

  • 3x1 - x2 ≥ -3
  • -0.3x1 + 1.2x2 ≤ 3
  • x1, x2 ≥ 0

Then which of the following is correct?

  1. The LPP has an unbounded solution.
  2. The LPP does not have an optimal solution.
  3. The LPP has no feasible region.
  4. The LPP has a finite optimal solution.
Correct Answer: (d) The LPP has a finite optimal solution.
View Solution

Graphical analysis of the constraints reveals a bounded feasible region. The objective function reaches a finite maximum within this region.


CUET PG Previous Year Question Paper