Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

This section includes 8666 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.

851.

If matrix \[A=\left[ \begin{matrix}    -5 & -8 & 0  \\    3 & 5 & 0  \\    1 & 2 & -1  \\ \end{matrix} \right]\] then find\[tr(A)+tr({{A}^{2}})+tr({{A}^{3}})+...+tr({{A}^{100}})\]

A. 100
B. 50
C. 200
D. None of these
Answer» D. None of these
852.

If \[A=\left[ \begin{matrix}    1 & 1  \\    1 & 1  \\ \end{matrix} \right]\] then \[{{A}^{100}}\]:

A. \[{{2}^{100}}A\]
B. \[{{2}^{99}}A\]
C. \[{{2}^{101}}A\]
D. None of above
Answer» C. \[{{2}^{101}}A\]
853.

If \[A=\left( \begin{matrix}    p & q  \\    0 & 1  \\ \end{matrix} \right)\], then \[{{A}^{8}}=\left( \begin{matrix}    {{p}^{8}} & q\left( \frac{{{p}^{8}}-1}{p-1} \right)  \\    0 & k  \\ \end{matrix} \right)\]. The value of k is

A. 1
B. 0   
C. 2
D. -1
Answer» B. 0   
854.

If \[P\left[ \begin{matrix}    \cos (\pi /6) & \sin (\pi /6)  \\    -\sin (\pi /6) & \cos (\pi /6)  \\ \end{matrix} \right],A=\left[ \begin{matrix}    1 & 1  \\    0 & 1  \\ \end{matrix} \right]\] and \[Q=PAP'\] then \[P'{{Q}^{2007}}P\] is equal to

A. \[\left[ \begin{matrix}    1 & 2007  \\    0 & 1  \\ \end{matrix} \right]\]
B. \[\left[ \begin{matrix}    1 & \sqrt{3}/2  \\    0 & 2007  \\ \end{matrix} \right]\]
C. \[\left[ \begin{matrix}    \sqrt{3}/2 & 2007  \\    0 & 1  \\ \end{matrix} \right]\]
D. \[\left[ \begin{matrix}    \sqrt{3}/2 & -1/2  \\    1 & 2007  \\ \end{matrix} \right]\]
Answer» B. \[\left[ \begin{matrix}    1 & \sqrt{3}/2  \\    0 & 2007  \\ \end{matrix} \right]\]
855.

If \[A=\left[ \begin{matrix}    1 & 2  \\    0 & 3  \\ \end{matrix} \right]\] is a \[2\times 2\] matrix and \[f(x)={{x}^{2}}-x+2\] is a polynomial, then what is f(A)?

A. \[\left[ \begin{matrix}    1 & 7  \\    1 & 7  \\ \end{matrix} \right]\]
B. \[\left[ \begin{matrix}    2 & 6  \\    0 & 8  \\ \end{matrix} \right]\]
C. \[\left[ \begin{matrix}    2 & 6  \\    0 & 6  \\ \end{matrix} \right]\]
D. \[\left[ \begin{matrix}    2 & 6  \\    0 & 7  \\ \end{matrix} \right]\]
Answer» C. \[\left[ \begin{matrix}    2 & 6  \\    0 & 6  \\ \end{matrix} \right]\]
856.

The matrix \[A=\left[ \begin{matrix}    1 & 3 & 2  \\    1 & x-1 & 1  \\    2 & 7 & x-3  \\ \end{matrix} \right]\] will have inverse for every real number x except for

A. \[x=\frac{11\pm \sqrt{5}}{2}\]
B. \[x=\frac{9\pm \sqrt{5}}{2}\]
C. \[x=\frac{11\pm \sqrt{3}}{2}\]
D. \[x=\frac{9\pm \sqrt{3}}{2}\]
Answer» B. \[x=\frac{9\pm \sqrt{5}}{2}\]
857.

If \[A=\left[ \begin{matrix}    2 & 2  \\    2 & 2  \\ \end{matrix} \right]\], then what is \[{{A}^{n}}\] equal to?

A. \[\left[ \begin{matrix}    {{2}^{n}} & {{2}^{n}}  \\    {{2}^{n}} & {{2}^{n}}  \\ \end{matrix} \right]\]
B. \[\left[ \begin{matrix}    2n & 2n  \\    2n & 2n  \\ \end{matrix} \right]\]
C. \[\left[ \begin{matrix}    {{2}^{2n-1}} & {{2}^{2n-1}}  \\    {{2}^{2n-1}} & {{2}^{2n-1}}  \\ \end{matrix} \right]\]
D. \[\left[ \begin{matrix}    {{2}^{2n+1}} & {{2}^{2n+1}}  \\    {{2}^{2n+1}} & {{2}^{2n+1}}  \\ \end{matrix} \right]\]
Answer» D. \[\left[ \begin{matrix}    {{2}^{2n+1}} & {{2}^{2n+1}}  \\    {{2}^{2n+1}} & {{2}^{2n+1}}  \\ \end{matrix} \right]\]
858.

If AB = O, then for the matrices \[A=\left[ \begin{matrix}    {{\cos }^{2}}\theta  & \cos \theta \sin \theta   \\    \cos \theta \sin \theta  & {{\sin }^{2}}\theta   \\ \end{matrix} \right]\] and \[B=\left[ \begin{matrix}    {{\cos }^{2}}\phi  & \cos \phi \sin \phi   \\    \cos \phi \sin \phi  & {{\sin }^{2}}\phi   \\ \end{matrix} \right],\theta -\phi \] is

A. An odd number of \[\frac{\pi }{2}\]
B. An odd multiple of \[\pi \]
C. An even multiple of \[\frac{\pi }{2}\]
D.             0
Answer» B. An odd multiple of \[\pi \]
859.

The element \[{{a}_{ij}}\] of square matrix is given by \[{{a}_{ij}}=(i+j)(i-j)\], then matrix A must be

A. Skew-symmetric matrix
B. Triangular matrix
C. Symmetric matrix
D. Null matrix
Answer» B. Triangular matrix
860.

Let \[A=\left[ \begin{matrix}    1 & 1 & 1  \\    1 & 1 & 1  \\    1 & 1 & 1  \\ \end{matrix} \right]\] be a square matrix of order 3. Then for any positive integer n, what is \[{{A}^{n}}\] equal to?

A. A
B. \[{{3}^{n}}A\]
C. \[({{3}^{n-1}})A\]
D. 3A
Answer» D. 3A
861.

If A is a square matrix such that \[(A-2I)(A+I)=O\]then \[{{A}^{-1}}=\]

A. \[\frac{A-I}{2}\]
B. \[\frac{A+I}{2}\]
C. \[2(A-I)\]
D. \[2A+I\]
Answer» B. \[\frac{A+I}{2}\]
862.

Number of square sub-matrices of order 2 (sub-matrix is obtained by deleting appropriate number of rows and columns in a given matrix) that can be formed from the matrix \[\left[ \begin{matrix}    1 & 2 & -1 & 4  \\    2 & 4 & 3 & 5  \\    -1 & -2 & 6 & -7  \\ \end{matrix} \right]\] is

A. 12
B. 15   
C. 18
D. \[{{2}^{12}}\]
Answer» D. \[{{2}^{12}}\]
863.

If \[A=\left[ \begin{matrix}    1 & 0  \\    -1 & 7  \\ \end{matrix} \right]\] and \[I=\left[ \begin{matrix}    1 & 0  \\    0 & 1  \\ \end{matrix} \right]\], then the value of k so that \[{{A}^{2}}=8A+kI\] is

A. \[k=7\]
B. \[k=-7\]
C. \[k=0\]
D. None of these
Answer» C. \[k=0\]
864.

Let \[A=\left[ \begin{align}   & \begin{matrix}    5 & 6 & 1  \\ \end{matrix} \\  & \begin{matrix}    2 & -1 & 5  \\ \end{matrix} \\ \end{align} \right]\]. Let there exist a matrix B such that \[AB=\left[ \begin{matrix}    35 & 49  \\    29 & 13  \\ \end{matrix} \right]\]. What is B equal to?

A. \[\left[ \begin{align}   & \begin{matrix}    5 & 1 & 4  \\ \end{matrix} \\  & \begin{matrix}    2 & 6 & 3  \\ \end{matrix} \\ \end{align} \right]\]
B. \[\left[ \begin{align}   & \begin{matrix}    2 & 6 & 3  \\ \end{matrix} \\  & \begin{matrix}    5 & 1 & 4  \\ \end{matrix} \\ \end{align} \right]\]
C. \[\left[ \begin{align}   & \begin{matrix}    5 & 2  \\ \end{matrix} \\  & \begin{matrix}    1 & 6  \\ \end{matrix} \\  & \begin{matrix}    4 & 3  \\ \end{matrix} \\ \end{align} \right]\]
D. \[\left[ \begin{align}   & \begin{matrix}    2 & 5  \\ \end{matrix} \\  & \begin{matrix}    6 & 1  \\ \end{matrix} \\  & \begin{matrix}    3 & 4  \\ \end{matrix} \\ \end{align} \right]\]
Answer» D. \[\left[ \begin{align}   & \begin{matrix}    2 & 5  \\ \end{matrix} \\  & \begin{matrix}    6 & 1  \\ \end{matrix} \\  & \begin{matrix}    3 & 4  \\ \end{matrix} \\ \end{align} \right]\]
865.

If A is any \[2\times 2\] matrix such that \[\left[ \begin{matrix}    1 & 2  \\    0 & 3  \\ \end{matrix} \right]A=\left[ \begin{matrix}    -1 & 0  \\    6 & 3  \\ \end{matrix} \right]\], then what is A equal to?

A. \[\left[ \begin{matrix}    -5 & 1  \\    -2 & 2  \\ \end{matrix} \right]\]
B. \[\left[ \begin{matrix}    -5 & -2  \\    1 & 2  \\ \end{matrix} \right]\]
C. \[\left[ \begin{matrix}    -5 & -2  \\    2 & 1  \\ \end{matrix} \right]\]
D. \[\left[ \begin{matrix}    5 & 2  \\    -2 & -1  \\ \end{matrix} \right]\]
Answer» D. \[\left[ \begin{matrix}    5 & 2  \\    -2 & -1  \\ \end{matrix} \right]\]
866.

If \[A={{[{{a}_{ij}}]}_{n\times n}}\] be a diagonal matrix with diagonal element all different and \[B={{[{{b}_{ij}}]}_{n\times n}}\] be some another matrix. Let \[AB={{[cij]}_{n\times n}}\]then \[{{c}_{ij}}\] is equal to

A. \[{{a}_{jj}}{{b}_{ij}}\]
B. \[{{a}_{ii}}\,{{b}_{ij}}\]
C. \[{{a}_{ij}}\,{{b}_{ij}}\]
D. \[{{a}_{ij}}\,{{b}_{ji}}\]
Answer» C. \[{{a}_{ij}}\,{{b}_{ij}}\]
867.

Consider the matrices \[A=\left[ \begin{matrix}    4 & 6 & -1  \\    3 & 0 & 2  \\    1 & -2 & 5  \\ \end{matrix} \right],B=\left[ \begin{align}   & \begin{matrix}    2 & 4  \\ \end{matrix} \\  & \begin{matrix}    0 & 1  \\ \end{matrix} \\  & \begin{matrix}    -1 & 2  \\ \end{matrix} \\ \end{align} \right],C=\left[ \begin{matrix}    3  \\    1  \\    2  \\ \end{matrix} \right]\] Out of the given matrix products, which one is not defined.

A. \[{{(AB)}^{T}}C\]
B. \[{{C}^{T}}C{{(AB)}^{T}}\]
C. \[{{C}^{T}}AB\]
D. \[{{A}^{T}}AB{{B}^{T}}C\]
Answer» C. \[{{C}^{T}}AB\]
868.

If \[A=\left[ \begin{matrix}    0 & 1 & 3  \\    1 & 2 & 3  \\    3 & a & 1  \\ \end{matrix} \right]\] and \[{{A}^{-1}}=\left[ \begin{matrix}    1/2 & -1/2 & 1/2  \\    -4 & 3 & c  \\    5/2 & -3/2 & 1/2  \\ \end{matrix} \right]\] Then the value of \[a+c\]is equal to

A.  1
B. 0
C. 2
D. None of these
Answer» C. 2
869.

Matrix A such that \[{{A}^{2}}=2A-I\], where I is the identity matrix, then for \[n\ge 2,\text{ }{{\text{A}}^{n}}\] is equal to

A. \[{{2}^{n-1}}A-(n-1)I\]
B. \[{{2}^{n-1}}A-I\]
C. \[nA-(n-1)I\]
D. \[nA-I\]
Answer» D. \[nA-I\]
870.

If A and B be two square matrices of order \[\lambda \]whose all the elements are essentially positive integers then the minimum value of \[tr\text{ (}A{{B}^{2}})\] is equal to                    

A. \[{{\lambda }^{3}}\]
B. \[{{\lambda }^{2}}\]
C. \[2{{\lambda }^{2}}\]
D. None of these
Answer» C. \[2{{\lambda }^{2}}\]
871.

Let \[A=\left[ \begin{matrix}    x+y & y  \\    2x & x-y  \\ \end{matrix} \right],B=\left[ \begin{matrix}    2  \\    -1  \\ \end{matrix} \right]\] and \[C=\left[ \begin{matrix}    3  \\    2  \\ \end{matrix} \right]\] If \[AB=C,\] then what is \[{{A}^{2}}\] equal to?

A. \[\left[ \begin{matrix}    6 & -10  \\    4 & 26  \\ \end{matrix} \right]\]
B. \[\left[ \begin{matrix}    -10 & 5  \\    4 & 24  \\ \end{matrix} \right]\]
C. \[\left[ \begin{matrix}    -5 & -6  \\    -4 & -20  \\ \end{matrix} \right]\]
D. \[\left[ \begin{matrix}    -5 & -7  \\    -5 & 20  \\ \end{matrix} \right]\]
Answer» B. \[\left[ \begin{matrix}    -10 & 5  \\    4 & 24  \\ \end{matrix} \right]\]
872.

If \[A=\left[ \begin{matrix}    0 & -1  \\    1 & 0  \\ \end{matrix} \right]\], then \[{{A}^{16}}\] is equal to:

A. \[\left[ \begin{matrix}    0 & -1  \\    1 & 0  \\ \end{matrix} \right]\]
B. \[\left[ \begin{matrix}    0 & 1  \\    1 & 0  \\ \end{matrix} \right]\]
C. \[\left[ \begin{matrix}    -1 & 0  \\    0 & 1  \\ \end{matrix} \right]\]
D. \[\left[ \begin{matrix}    1 & 0  \\    0 & 1  \\ \end{matrix} \right]\]
Answer» E.
873.

Elements of a matrix A of order \[10\times 10\] are defined as \[{{a}_{ij}}={{w}^{i+j}}\] (where w is cube root of unity), then trof the matrix is

A. 0
B. 1
C. 3
D. None of these
Answer» E.
874.

sLet \[A=\left[ \begin{matrix}    1 & 2  \\    3 & 4  \\ \end{matrix} \right]\] and \[B=\left[ \begin{matrix}    a & 0  \\    0 & b  \\ \end{matrix} \right]\] where a, b are natural numbers, then which one of the following is correct?

A. There exist more than one but finite number of B's such that AB = BA
B. There exists exactly one B such that AB = BA
C. There exist infinitely many B's such that AB=BA
D. There cannot exist any B such that AB = BA
Answer» D. There cannot exist any B such that AB = BA
875.

If number of elements is 20 then how many different types of matrices can be formed if number of rows is always even?

A. 3
B. 4
C. 5
D. 6
Answer» C. 5
876.

The matrix \[A=\left[ \begin{matrix}    -5 & -8 & 0  \\    3 & 5 & 0  \\    1 & 2 & -1  \\ \end{matrix} \right]\] is

A. Idempotent matrix
B. Involutory matrix
C. Nilpotent matrix
D. None of these
Answer» C. Nilpotent matrix
877.

Which of the following is not a statement?

A. Please do me a favour
B. 2 is an even integer
C. \[2+1=3\]
D. The number 17 is prime
Answer» B. 2 is an even integer
878.

If p and q are two statement then \[(p\leftrightarrow \tilde{\ }q)\] is true when-

A. p and q both are true
B. p and q both are false
C. p is false and q is true
D. None of these
Answer» D. None of these
879.

The false statement of the following is

A. \[p\wedge (\tilde{\ }p)\] is a contradiction
B. \[(p\Rightarrow q)\Leftrightarrow (\tilde{\ }q\Rightarrow \tilde{\ }p)\] is a contradiction
C. \[\tilde{\ }(\tilde{\ }p)\Leftrightarrow p\] is a tautology
D. \[p\vee (\tilde{\ }p)\Leftrightarrow p\] is a tautology
Answer» C. \[\tilde{\ }(\tilde{\ }p)\Leftrightarrow p\] is a tautology
880.

If p is nay statement, then which of the following is a tautology?

A. \[p\wedge f\]
B. \[p\vee f\]
C. \[p\vee (\tilde{\ }p)\]
D. \[p\wedge t\]
Answer» D. \[p\wedge t\]
881.

\[\tilde{\ }(p\Rightarrow q)\Leftrightarrow \tilde{\ }p\vee \tilde{\ }q\] is

A. A tautology
B. A contradiction
C. Neither a tautology nor a contradiction
D. Cannot come to any conclusion
Answer» D. Cannot come to any conclusion
882.

The contrapositive of the statement, ?If I do not secure good marks then I cannot go for engineering?, is

A. If I secure good marks, then I go for engineering
B. If I go for engineering then I secure good marks
C. If I cannot go for engineering then I do not secure good marks
D. None
Answer» C. If I cannot go for engineering then I do not secure good marks
883.

Let p be the proposition: Mathematics is a interesting and let q be the propositions that Mathematics is difficult, then the symbol \[p\wedge q\]means

A. Mathematics is interesting ipllies that Mathematics is difficult
B. Mathematics is interesting impels and is implied by Mathematics is difficult
C. Mathematics is interesting and Mathematics is difficult
D. Mathematics is interesting or Mathematics is difficult
Answer» D. Mathematics is interesting or Mathematics is difficult
884.

Which of the following is a contradiction?

A. \[(p\wedge q)\wedge \tilde{\ }(p\vee q)\]
B. \[p\vee (-p\wedge q)\]
C. \[(p\Rightarrow q)\Rightarrow p\]
D. None of these
Answer» B. \[p\vee (-p\wedge q)\]
885.

If p: 4 is an even prime number, q: 6 is a divisor of 12 and r: the HCF of 4 and 6 is 2, then which one of the following is true?

A. \[(p\wedge q)\]
B. \[(p\vee q)\wedge \tilde{\ }r\]
C. \[\tilde{\ }(q\wedge r)p\]
D. \[\tilde{\ }p\vee (q\wedge r)\]
Answer» E.
886.

In the truth table for the statement \[(p\to q)\leftrightarrow (\tilde{\ }p\vee q),\] the last column has the truth value in the following order is

A. \[TTFF\]
B. \[FFFF\]
C. \[TTTT\]
D. \[FTFT\]  
Answer» D. \[FTFT\]  
887.

The contrapositive of the inverse of \[p\Rightarrow \tilde{\ }q\] is

A. \[\tilde{\ }q\Rightarrow p\]
B. \[p\Rightarrow q\]
C. \[\tilde{\ }q\Rightarrow \tilde{\ }p\]
D. \[\tilde{\ }p\Rightarrow \tilde{\ }q\]
Answer» B. \[p\Rightarrow q\]
888.

The negation of the statement ?A circle is an ellipse?? is

A. An ellipse is a circle
B. An ellipse is not a circle
C. A circle is not an ellipse
D. A circle is an ellipse
Answer» D. A circle is an ellipse
889.

Which of the following is not logically equivalent to the proposition: 'A real number is either rational or irrational.'?

A. If a number is neither rational n nor irrational then it is not real
B. If a number is not a rational or not an irrational, then it is not real
C. If a number is not real, then it is neither rational nor irrational
D. If a number is real, then it is rational or irrational.
Answer» C. If a number is not real, then it is neither rational nor irrational
890.

The propositions \[(p\Rightarrow \tilde{\ }p)\wedge (\tilde{\ }p\Rightarrow p)\] is a

A. Tautology and contradiction
B. Neither tautology nor contradiction
C. Contradiction
D. Tautology
Answer» D. Tautology
891.

The negation of the statement \[(p\wedge q)\to (\tilde{\ }p\vee r)\]is

A. \[(p\wedge q)\vee (p\vee \tilde{\ }r)\]
B. \[(p\wedge q)\vee (p\wedge \tilde{\ }r)\]
C. \[(p\wedge q)\wedge (p\wedge \tilde{\ }r)\]
D. \[p\vee q\]
Answer» D. \[p\vee q\]
892.

If p: Ashok works hard  q: Ashok gets good grade The verbal form for \[(\tilde{\ }p\to q)\] is

A. If Ashok works hard then gets good grade
B. If Ashok does not work hard then he gets good grade
C. If Ashok does not work hard then he does not get good grade
D. Ashok works hard if and only if he gets grade
Answer» C. If Ashok does not work hard then he does not get good grade
893.

If \[p\Rightarrow (q\vee r)\] is false, then the truth values of \[p,q,r\] are respectively

A. \[T,F,F\]
B. \[F,F,F\]
C. \[F,T,T\]
D. \[T,T,F\]
Answer» B. \[F,F,F\]
894.

Negation of the conditional: 'If it rains, I shall go to school'? is

A. It rains and I shall go to school
B. It runs and I shall not go to school
C. It does not rains and I shall go to school
D. None of these
Answer» C. It does not rains and I shall go to school
895.

If :p Raju is tall and q: Raju is intelligent, then the symbolic statement \[\tilde{\ }p\vee q\] means

A. Raju is not tall or he is intelligent.
B. Raju is tall or he is intelligent
C. Raju is not tall and he is intelligent
D. Raju is not tall implies he is intelligent
Answer» B. Raju is tall or he is intelligent
896.

Let p and q be any two logical statements and \[r:p\to (\tilde{\ }p\vee q).\] If r has a truth value F, then the truth values of p and q are respectively:

A. F, F
B. T, T
C. T, F
D. F, T
Answer» D. F, T
897.

Identify the false statements

A. \[\tilde{\ }[p\vee (\tilde{\ }q)]\equiv (\tilde{\ }p)\vee q\]
B. \[[p\vee q]\vee (\tilde{\ }p)\] is a tautology
C. \[[p\wedge q)\wedge (\tilde{\ }p)\] is a contradiction
D. \[\tilde{\ }[p\vee q]\equiv (\tilde{\ }p)\vee (\tilde{\ }q)\]
Answer» E.
898.

The inverse of the statement \[(p\wedge \tilde{\ }q)\to r\] is

A. \[\tilde{\ }(p\vee \tilde{\ }q)\to \tilde{\ }r\]
B. \[(\tilde{\ }p\wedge q)\to \tilde{\ }r\]
C. \[(\tilde{\ }p\vee q)\to \tilde{\ }r\]
D. None of these
Answer» D. None of these
899.

The statement \[p\to (q\to p)\]is equivalent to

A. \[p\to (p\to q)\]
B. \[p\to (p\vee q)\]
C. \[p\to (p\wedge q)\]
D. \[p\to (p\leftrightarrow q)\]
Answer» E.
900.

Which of the following is always true?

A. \[(\tilde{\ }p\vee \tilde{\ }q)\equiv (p\wedge q)\]
B. \[(p\to q)\equiv (\tilde{\ }q\to \tilde{\ }p)\]
C. \[\tilde{\ }(p\to \tilde{\ }q)\equiv (p\wedge \tilde{\ }q)\]
D. \[\tilde{\ }(p\leftrightarrow q)\equiv (p\to q)\to (q\to p)\]
Answer» C. \[\tilde{\ }(p\to \tilde{\ }q)\equiv (p\wedge \tilde{\ }q)\]