Let A be a 2 × 2 matrix Statement 1 : adj (adj A) = A Statement

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

1.

If P = open square brackets table row 1 straight alpha 3 row 1 3 3 row 2 4 4 end table close square brackets is the adjoint of a 3 x3 matrix A and |A| = 4, then α is equal to 

  • 4

  • 11

  • 5

  • 5

547 Views

2.

Let A = open square brackets table row 1 0 0 row 2 1 0 row 3 2 1 end table close square brackets. If u1 and u2 are column matrices such that Au1 = open square brackets table row 1 row 0 row 0 end table close square brackets and Au2 = open square brackets table row 0 row 1 row 0 end table close square brackets, then u1 +u2 is equal to

  • open square brackets table row cell negative 1 end cell row 1 row 0 end table close square brackets
  • open square brackets table row cell negative 1 end cell row cell space space space 1 end cell row cell negative 1 end cell end table close square brackets
  • open square brackets table row cell negative 1 end cell row cell negative 1 end cell row 0 end table close square brackets
  • open square brackets table row cell negative 1 end cell row cell negative 1 end cell row 0 end table close square brackets
480 Views

3.

Let A and B be two symmetric matrices of order 3.
Statement-1: A(BA) and (AB)A are symmetric matrices.
Statement-2: AB is symmetric matrix if matrix multiplication of A with B is commutative.

  • Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1.

  • Statement-1 is true, Statement-2 is true; Statement-2 is true; Statement-2 is not a correct explanation for Statement-1.

  • Statement-1 is true, Statement-2 is false. 

  • Statement-1 is true, Statement-2 is false. 

191 Views

4.

The number of 3 × 3 non-singular matrices, with four entries as 1 and all other entries as 0, is 

  • less than 4

  • 5

  • 6

  • 6

178 Views

Advertisement
5.

Let f : R → R be defined by
straight f left parenthesis straight x right parenthesis space equals space open curly brackets table attributes columnalign left end attributes row cell straight k minus 2 straight x comma if space straight x space less or equal than space minus 1 end cell row cell 2 straight x space plus 3 comma space if space straight x greater than negative 1 end cell end table close
If f has a local minimum at x = - 1 then a possible value of k is

  • 1

  • 0

  • -1/2

  • -1/2

137 Views

6.

If S is the set of distinct values of 'b' for which the following system of linear equations
x + y + z = 1
x + ay + z = 1
ax + by + z = 0
has no solution, then S is

  • a singleton

  • an empty set

  • an infinite set

  • an infinite set

297 Views

7.

Let  ω be a complex number such that 2ω +1 = z where z = √-3. if

open vertical bar table row 1 1 1 row 1 cell negative straight omega squared end cell cell straight omega squared end cell row 1 cell straight omega squared end cell cell straight omega to the power of 7 end cell end table close vertical bar space equals space 3 straight k
then k is equal to 

  • 1

  • -z

  • z

  • z

307 Views

8.

Let a, b, c be such that 0 (a +c) ≠ . If open vertical bar table row cell space space space straight a end cell cell straight a plus 1 end cell cell space space straight a minus 1 end cell row cell negative straight b end cell cell straight b plus 1 end cell cell space space straight b minus 1 end cell row cell space space space straight c end cell cell space straight c minus 1 end cell cell space space straight c plus 1 end cell end table close vertical bar plus open vertical bar table row cell straight a plus 1 end cell cell straight b plus 1 end cell blank row cell straight a minus 1 end cell cell straight b minus 1 end cell cell straight c plus 1 end cell row cell left parenthesis negative 1 right parenthesis to the power of straight n plus 2 end exponent straight a end cell cell left parenthesis negative 1 right parenthesis to the power of straight n plus 1 end exponent straight b end cell cell left parenthesis negative 1 right parenthesis to the power of straight n space straight c end cell end table close vertical bar space equals space 0,then the value of 'n' is 

  • 0

  • any even integer

  • any odd integer

  • any odd integer

167 Views

Advertisement
Advertisement

9.

Let A be a 2 × 2 matrix
Statement 1 : adj (adj A) = A
Statement 2 : |adj A| = |A|

  • Statement–1 is true, Statement–2 is true, Statement–2 is a correct explanation for statement–1

  • Statement–1 is true, Statement–2 is true; Statement–2 is not a correct explanation for statement–1.

  • Statement–1 is true, statement–2 is false.

  • Statement–1 is true, statement–2 is false.


A.

Statement–1 is true, Statement–2 is true, Statement–2 is a correct explanation for statement–1

adj(adjA) = |A|n – 2A,
where |A| = determinant of A but n = 2
⇒ A also |adj A| = |A|n – 1
⇒ |A| Statement–1 is true and Statement–2 is also true and Statement–2 is correct explanation of Statement–1.

178 Views

Advertisement
10.

If A and B are square matrices of size n × n such that A2 − B2 = (A − B) (A + B), then which of the following will be always true?

  • A = B

  • AB = BA

  • either of A or B is a zero matrix

  • either of A or B is a zero matrix

223 Views

Advertisement