Explore topic-wise MCQs in Mathematics.

This section includes 72 Mcqs, each offering curated multiple-choice questions to sharpen your Mathematics knowledge and support exam preparation. Choose a topic below to get started.

1.

If \(A=\left[ \begin{matrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \\ \end{matrix} \right]\) then A-1 is-

A. -A
B. A
C. I
D. 0
Answer» C. I
2.

If the determinant \(\left| {\begin{array}{*{20}{c}} x&1&3\\ 0&0&1\\ 1&x&4 \end{array}} \right| = 0\) then what is x equal to?

A. 02 or 2
B. -3 or 3
C. -1 or 1
D. 3 or 4
Answer» D. 3 or 4
3.

If A and B are square matrices of order 3 such that |A| = -1, |B| = 3 then |3 AB| is equal to -

A. -9
B. -81
C. -27
D. 81
Answer» C. -27
4.

If B is a non-singular matrix and A is a square matrix, then the value of det (B-1 AB) is equal to

A. det (B)
B. det (A)
C. det (B-1)
D. det (A-1)
Answer» C. det (B-1)
5.

​If [x] denotes the greatest integer ≤ x, then the system of linear equations [sin θ]x + [-cos θ]y = 0 and [cot θ]x + y = 0

A. Have infinitely many solutions if \(\theta \in \left( {\frac{\pi }{2},{\rm{\;}}\frac{{2\pi }}{3}} \right)\) and has a unique solution if \(\theta \in \left( {\pi ,{\rm{\;}}\frac{{7\pi }}{6}} \right)\).
B. Has unique solution if \(\theta \in \left( {\frac{\pi }{2},{\rm{\;}}\frac{{2\pi }}{3}} \right) \cup \left( {\pi ,{\rm{\;}}\frac{{7\pi }}{6}} \right)\).
C. Has unique solution if \(\theta \in \left( {\frac{\pi }{2},{\rm{\;}}\frac{{2\pi }}{3}} \right)\) and have infinitely many solutions if \(\theta \in \left( {\pi ,{\rm{\;}}\frac{{7\pi }}{6}} \right)\).
D. Have infinitely many solutions if \(\theta \in \left( {\frac{\pi }{2},\;\frac{{2\pi }}{3}} \right) \cup \left( {\pi ,\;\frac{{7\pi }}{6}} \right)\).
Answer» B. Has unique solution if \(\theta \in \left( {\frac{\pi }{2},{\rm{\;}}\frac{{2\pi }}{3}} \right) \cup \left( {\pi ,{\rm{\;}}\frac{{7\pi }}{6}} \right)\).
6.

If a, b, c are real numbers, then the value of the determinant \(\left| {\begin{array}{*{20}{c}} {1 - {\rm{a}}}&{{\rm{a}} - {\rm{b}} - {\rm{c}}}&{{\rm{b}} + {\rm{c}}}\\ {1 - {\rm{b}}}&{{\rm{b}} - {\rm{c}} - {\rm{a}}}&{{\rm{c}} + {\rm{a}}}\\ {1 - {\rm{c}}}&{{\rm{c}} - {\rm{a}} - {\rm{b}}}&{{\rm{a}} + {\rm{b}}} \end{array}} \right|\) is

A. 0
B. (a - b) (b - c) (c - a)
C. (a + b + c) 2
D. (a + b + c) 3
Answer» B. (a - b) (b - c) (c - a)
7.

If the value of the determinant \(\left[ {\begin{array}{*{20}{c}} {\rm{a}}&1&1\\ 1&{\rm{b}}&1\\ 1&1&{\rm{c}} \end{array}} \right]\) is positive, where a ≠ b ≠ c, then the value of abc is

A. cannot be less than 1
B. is greater than -8
C. is less than -8
D. must be greater than 8
Answer» C. is less than -8
8.

A matrix Mr is defined as \(M_r = \begin{bmatrix} r & r - 1 \\\ r - 1 & r \end{bmatrix} r \in N\), then the value of det (M1) + det(M2) + ... + det(M2015) is

A. 20142
B. 20132
C. 2015
D. 20152
Answer» E.
9.

If \(A=\left[ \begin{matrix}{{e}^{t}} & {{e}^{-t}}\text{cos }\!\!~\!\!\text{ }t & {{e}^{-t}}\text{sin }\!\!~\!\!\text{ }t \\{{e}^{t}} & -{{e}^{-t}}\text{cos }\!\!~\!\!\text{ }t-{{e}^{-t}}\text{sin }\!\!~\!\!\text{ }t & -{{e}^{-t}}\text{sin }\!\!~\!\!\text{ }t+{{e}^{-t}}\text{cos }\!\!~\!\!\text{ }t \\{{e}^{t}} & 2{{e}^{-t}}\text{sin }\!\!~\!\!\text{ }t & -2{{e}^{-t}}\text{cos }\!\!~\!\!\text{ }t \\\end{matrix} \right]\) then A is:

A. Invertible for all t ∈ R
B. Invertible only if t = π
C. Not invertible for any t ∈ R
D. Invertible only if \(\text{t}=\frac{\pi }{2}\)
Answer» B. Invertible only if t = π
10.

Factors of the determinant \(\left| {\begin{array}{*{20}{c}} a&{b + c}&{{a^2}}\\ b&{c + a}&{{b^2}}\\ c&{a + b}&{{c^2}} \end{array}} \right|\)

A. (a - b), (b - c), (c - a), (a + b + c)
B. (a + b), (b + c), (c + a), (a + b + c)
C. (a + b), (b - c), (c + a), (a + b + c)
D. (a2 + b2), (b2 + c2), (c2 + a2)
Answer» B. (a + b), (b + c), (c + a), (a + b + c)
11.

Let \({\rm{a}}{{\rm{x}}^3} + {\rm{b}}{{\rm{x}}^2} + {\rm{cx}} + {\rm{d}} = \left| {\begin{array}{*{20}{c}} {{\rm{x}} + 1}&{2{\rm{x}}}&{3{\rm{x}}}\\ {2{\rm{x}} + 3}&{{\rm{x}} + 1}&{\rm{x}}\\ {2 - {\rm{x}}}&{3{\rm{x}} + 4}&{5{\rm{x}} - 1} \end{array}} \right|\)What is the value of a + b + c + d?

A. 62
B. 63
C. 65
D. 68
Answer» C. 65
12.

Let \({\rm{a}}{{\rm{x}}^3} + {\rm{b}}{{\rm{x}}^2} + {\rm{cx}} + {\rm{d}} = \left| {\begin{array}{*{20}{c}} {{\rm{x}} + 1}&{2{\rm{x}}}&{3{\rm{x}}}\\ {2{\rm{x}} + 3}&{{\rm{x}} + 1}&{\rm{x}}\\ {2 - {\rm{x}}}&{3{\rm{x}} + 4}&{5{\rm{x}} - 1} \end{array}} \right|\)What is the value of c?

A. -1
B. 34
C. 35
D. 50
Answer» D. 50
13.

If \(\left| {\begin{array}{*{20}{c}} 5&a\\ a&2 \end{array}} \right| = \left| {\begin{array}{*{20}{c}} 2&1\\ 3&2 \end{array}} \right|\), then the values of a are:

A. ± 1
B. ± 2
C. ± 3
D. ± 4
Answer» D. ± 4
14.

Area of the triangle formed by the lines 7x - 2y + 10 = 0, 7x + 2y - 10 = 0 and y + 2 = 0 is

A. 8
B. 14
C. 16
D. 18/7
Answer» C. 16
15.

If \(A = \left[ {\begin{array}{*{20}{c}} a&b&c\\ b&c&a\\ c&a&b \end{array}} \right],\) where a, b, c are real positive numbers such that abc = 1 and ATA = I then the equation that holds true among the following is

A. a + b + c = 1
B. a2 + b2 + c2 = 1
C. ab + bc + ca = 0
D. a3 + b3 + c3 = 4
Answer» C. ab + bc + ca = 0
16.

If a, b, c are the roots of equation \(x^3-3x^2 + 3x + 7=0\), then the value of \(\begin{vmatrix} 2bc-a^2 & c^2 & b^2 \\\ c^2 & 2ac-b^2 & a^2 \\\ b^2 & a^2 & 2ab-c^2 \end{vmatrix}\) is

A. 9
B. 27
C. 81
D. 0
Answer» E.
17.

Let \(A = \left| {\begin{array}{*{20}{c}} p&q\\ r&s \end{array}} \right|\)where p, q, r and s are any four different prime numbers less than 20. What is the maximum value of the determinant?

A. 215
B. 311
C. 317
D. 323
Answer» D. 323
18.

If p + q + r = a + b + c = 0, then the determinant \(\left| {\begin{array}{*{20}{c}} {{\rm{pa}}}&{{\rm{qb}}}&{{\rm{rc}}}\\ {{\rm{qc}}}&{{\rm{ra}}}&{{\rm{pb}}}\\ {{\rm{rb}}}&{{\rm{pc}}}&{{\rm{qa}}} \end{array}} \right|\) equals

A. 0
B. 1
C. pa + qb + rc
D. pa + qb + rc + a + b + c
Answer» B. 1
19.

If \(\left[ {\begin{array}{*{20}{c}} x&{ - 3i}&1\\ y&1&i\\ 0&{2i}&{ - i} \end{array}} \right] = 6 + 11i\), then what are the values of x and y respectively?

A. -3, 4
B. 3, 4
C. 3, -4
D. -3, -4
Answer» B. 3, 4
20.

An equilateral triangle has each side equal to a. If the co-ordinates of its vertices are (x1, y1); (x2, y2): (x3, y3) then the square of the determinant \(\begin{vmatrix} x_1 & y_1 & 1 \\\ x_2 & y_2& 1 \\\ x_2 & y_2 & 1 \end{vmatrix}\) equals:

A. None of these
B. 4a2
C. 3a4
D. \(\dfrac{3a^4}{4}\)
Answer» E.
21.

If \({\rm{A}} = \left[ {\begin{array}{*{20}{c}} {\rm{\alpha }}&2\\ 2&{\rm{\alpha }} \end{array}} \right]\) and det (A3) = 125, then α is equal to

A. ± 1
B. ± 2
C. ± 3
D. ± 5
Answer» D. ± 5
22.

If a square matrix A is such that AAT = I = ATA, then |A| is equal to -

A. 0
B. ± 1
C. ± 2
D. None of these
Answer» C. ± 2
23.

Let \(\mathop \sum \limits_{k = 1}^{10} f\left( {a + k} \right) = 16\left( {{2^{10}} - 1} \right),{\rm{}}\) where the function \(f\) satisfies f(x + y) = f(x)f(y) for all natural numbers x, y and f(1) = 2. Then the natural number 'a' is:

A. 2
B. 16
C. 4
D. 3
Answer» E.
24.

If A is a square matrix of order 3 and det A = 5, then what is det [(2A)-1] equal to ?

A. 1/10
B. 2/5
C. 8/5
D. 1/40
Answer» E.
25.

If A is an invertible matrix of order n and k is any positive real number, then the value of [det(kA)]-1 det A is

A. k-n
B. k-1
C. kn
D. nk
Answer» B. k-1
26.

If a + b + c = 4 and ab + bc + ca = 0, then what is the value of the following determinant?\(\left| {\begin{array}{*{20}{c}} {{a}}&{{b}}&{{c}}\\ {{b}}&{{c}}&{{a}}\\ {{c}}&{{a}}&{{b}} \end{array}} \right|\)

A. 32
B. -64
C. -128
D. 64
Answer» C. -128
27.

\(\mathop {\lim }\limits_{x \to 1} \frac{{1 - \sqrt x }}{{{{\cos }^{ - 1}}x}}\) is equal to

A. 0
B. \(\frac{1}{2}\)
C. \(\frac{1}{4}\)
D. 1
Answer» B. \(\frac{1}{2}\)
28.

If \(A = \left( {\begin{array}{*{20}{c}} 9&6\\ 8&7 \end{array}} \right)\) then det (A99 – A98) is

A. 1
B. 48
C. 0
D. 299
Answer» D. 299
29.

Consider the following statements in respect of the determinant \(\left| {\begin{array}{*{20}{c}} {{{\cos }^2}\frac{\alpha }{2}}&{{{\sin }^2}\frac{\alpha }{2}}\\ {{{\sin }^2}\frac{\beta }{2}}&{{{\cos }^2}\frac{\beta }{2}} \end{array}} \right|\)Where α, β are complementary angles1. The value of the determinant is \(\frac{1}{{√ 2 }}\cos \left( {\frac{{\alpha - \beta }}{2}} \right)\;\)2. The maximum value of the determinant is \(\frac{1}{\sqrt2}\)Which of the above statements is/are correct?

A. 1 only
B. 2 only
C. Both 1 and 2
D. Neither 1 nor 2
Answer» D. Neither 1 nor 2
30.

If A = \(\left| {\begin{array}{*{20}{c}} 1& -2\\ 3&\rm -k \end{array}} \right|\) is a singular matrix, then value of k

A. 0
B. -6
C. 6
D. 8
Answer» D. 8
31.

If a1, a2, a3, _ _ _ _ _, a9 are in GP, then what is the value of the following determinant?\(\left| {\begin{array}{*{20}{c}} {{ln\:a_1}}&{{ln\:a_2}}&{{ln\:a_3}}\\ {{ln\:a_4}}&{{ln\:a_5}}&{{ln\:a_6}}\\ {{ln\:a_7}}&{{ln\:a_8}}&{{ln\:a_9}} \end{array}} \right|\)

A. 0
B. 1
C. 2
D. 4
Answer» B. 1
32.

If a complex number is z = \(\left\{ {\frac{{3\; + \;4i}}{{1\; - \;2i}}} \right\}\), then |z| will be:

A. \(\sqrt{5}\)
B. 1
C. 2\(\sqrt{5}\)
D. \(\frac{1}{\sqrt{5}}\)
Answer» B. 1
33.

Let A = [aij] and B = [bij] be two square matrices of order n and det(A) denote the determinant of A. Then, which of the following is not correct:

A. If A is a diagonal matrix, then det(A) = a11 a22 ... ann.
B. det(AB) = det(A) det(B).
C. det(cA) = c [det(A)].
D. det(A) = det(AT), where AT denotes the transpose of the matrix A.
Answer» D. det(A) = det(AT), where AT denotes the transpose of the matrix A.
34.

If the system of equation x + 2y - 3z = 2, (k + 3) z = 3, (2k + 1) y + z = 2 is consistent, then K is

A. -3 and \( - \frac{1}{2}\)
B. \( - \frac{1}{2}\)
C. 1
D. 2
Answer» B. \( - \frac{1}{2}\)
35.

(cos 5θ - i sin 5θ)2 is same as

A. cos 10θ + i sin 10θ
B. cos 25θ - i sin 25θ
C. (cos θ + i sin θ)-10
D. (c0s θ - i sin θ)-10
Answer» D. (c0s θ - i sin θ)-10
36.

If \(\left| {\begin{array}{*{20}{c}} {a - b - c}&{2a}&{2a}\\ {2b}&{b - c - a}&{2b}\\ {2c}&{2c}&{c - a - b} \end{array}} \right| = \left( {a + b + c} \right){(x + a + b + c)^2}\), x ≠ 0 and a + b + c ≠ 0, then ‘x’ is equal to:

A. abc
B. -(a + b + c)
C. 2(a + b + c)
D. -2(a + b + c)
Answer» E.
37.

If a + b + c = 0, then one of the solutions of\(\left| {\begin{array}{*{20}{c}} {a - x}&c&b\\ c&{b - x}&a\\ b&a&{c - x} \end{array}} \right| = 0\) is

A. x = a
B. \(x = \sqrt {\frac{{3\left( {{a^2} + {b^2} + {c^2}} \right)}}{2}} \)
C. \(x = \sqrt {\frac{{2\left( {{a^2} + {b^2} + {c^2}} \right)}}{3}} \)
D. x = 0
Answer» E.
38.

Find the condition on k, so that the system of equations: x + 3y = 5 and 2x + ky = 8 has a unique solution.

A. k = 6
B. k ≠ 6
C. k ≠ 4
D. k = 4
Answer» C. k ≠ 4
39.

If x + a + b + c = 0, then what is the value of \(\left| {\begin{array}{*{20}{c}} {x + a}&b&c\\ a&{x + b}&c\\ a&b&{x + c} \end{array}} \right|?\)

A. 0
B. (a + b + c)2
C. a2 + b2 + c2
D. a + b + c - 2
Answer» B. (a + b + c)2
40.

Let A and B be two invertible matrices of order 3 × 3. If det(ABAT) = 8 and det(AB(-1)) = 8, then det(BA(-1) BT) is equal to:

A. \(\frac{1}{4}\)
B. 1
C. \(\frac{1}{16}\)
D. 16
Answer» D. 16
41.

Let p, q and r be three distinct positive real numbers. If \(\rm D = \left| {\begin{array}{*{20}{c}} \rm p&\rm q&\rm r\\ \rm q&\rm r&\rm p\\ \rm r&\rm p&\rm q \end{array}} \right|,\) then which one of the following is correct?

A. D < 0
B. D ≤ 0
C. D > 0
D. D ≥ 0
Answer» C. D > 0
42.

A is a square matrix of order 3 such that its determinate is 4. What is the determinant of its transpose?

A. 64
B. 36
C. 32
D. 4
Answer» E.
43.

If \(\left| {\begin{array}{*{20}{c}} {\rm{x}}&{\rm{y}}&0\\ 0&{\rm{x}}&{\rm{y}}\\ {\rm{y}}&0&{\rm{x}} \end{array}} \right| = 0\), then which one of the following is correct?

A. \(\frac{{\rm{x}}}{{\rm{y}}}\) is one of the cube roots of unity
B. x is one of the cube roots of unity
C. y is one of the cube roots of unity
D. \(\frac{{\rm{x}}}{{\rm{y}}}\) is one of the cube roots of -1
Answer» E.
44.

If A + B + C = \(\pi \), then, the value of \(\left| {\begin{array}{*{20}{c}} {\sin \left( {A + B + C} \right)}&{\sin B}&{\cos C}\\ { - \sin B}&0&{\tan A}\\ {\cos \left( {A + B} \right)}&{ - \tan A}&0 \end{array}} \right|\) is

A. 0
B. 1
C. 2 sin A sin B
D. 2
Answer» B. 1
45.

If x, y, z are distinct real numbers and \(\left| {\begin{array}{*{20}{c}} x&{{x^2}}&{2 + {x^3}}\\ y&{{y^2}}&{2 + {y^3}}\\ z&{{z^2}}&{2 + {z^3}} \end{array}} \right| = 0\), then xyz =

A. 1
B. -1
C. 2
D. -2
Answer» E.
46.

Let \(f(x) = \left| {\begin{array}{*{20}{c}} {{x^3}}&{\sin x}&{\cos x}\\ 6&{ - 1}&0\\ p&{{p^2}}&{{p^3}} \end{array}} \right|\), where p is a constant, then \(\frac{{{d^3}}}{{d{x^3}}}\left( {f(x)} \right)\) at x = 0 is

A. p
B. p + p2
C. p + p3
D. independent of p
Answer» E.
47.

Let matrix B be the adjoint of a square matrix A, l be the identify matrix of same order as A. If k (≠ 0) is the determinate of the matrix A, then what is AB equal to?

A. l
B. kl
C. k2l
D. (1/k)l
Answer» C. k2l
48.

Let \(Δ = \left| {\begin{array}{*{20}{c}} 1&{\sin \theta }&1\\ { - \sin \theta }&1&{\sin \theta }\\ { - 1}&{ - \sin \theta }&1 \end{array}} \right|\) The Δ lies in the interval

A. [3, 4]
B. [2, 4]
C. [1, 4]
D. None of these
Answer» C. [1, 4]
49.

If A is a square matrix of order n > 1, then which one of the following is correct?

A. det (-A) = det A
B. det (-A) = (-1)n det A
C. det (-A) = -det A
D. det (-A) = n det A
Answer» C. det (-A) = -det A
50.

If u, v and w (all positive) are the pth, qth and rth terms of a GP, then the determinant of the Matrix \(\left( {\begin{array}{*{20}{c}} {lnu}&p&1\\ {lnv}&q&1\\ {lnw}&r&1 \end{array}} \right)is\)

A. 0
B. 1
C. (p - q) (q - r)(r - p)
D. ln u × ln v × ln w
Answer» B. 1