WB JEE 2019 | Matrices and Determinants Question 47 | Mathematics

PREVIOUS NEXT

WB JEE 2019

MCQ (Single Correct Answer)

-0.25

If M is any square matrix of order 3 over R and if M' be the transpose of M, then adj(M') $$-$$ (adj M)' is equal to

null matrix

identity matrix

WB JEE 2019

MCQ (Single Correct Answer)

-0.25

If $$A = \left( {\matrix{ 5 & {5x} & x \cr 0 & x & {5x} \cr 0 & 0 & 5 \cr } } \right)$$ and $$|A{|^2} = 25$$, then | x | is equal to

$${1 \over 5}$$

5²

WB JEE 2019

MCQ (Single Correct Answer)

-0.25

Let A and B be two square matrices of order 3 and AB = O₃, where O₃ denotes the null matrix of order 3. Then,

must be A = O₃ , B = O₃

if A $$ \ne $$ O₃, must be B $$ \ne $$ O₃

if A = O₃, must be B $$ \ne $$ O₃

may be A $$ \ne $$ O₃, B $$ \ne $$ O₃

WB JEE 2019

MCQ (Single Correct Answer)

-0.5

The system of equations

$$\eqalign{ & \lambda x + y + 3z = 0 \cr & 2x + \mu y - z = 0 \cr & 5x + 7y + z = 0 \cr} $$

has infinitely many solutions in R. Then,

$$\lambda $$ = 2, $$\mu $$ = 3

$$\lambda $$ = 1, $$\mu $$ = 2

$$\lambda $$ = 1, $$\mu $$ = 3

$$\lambda $$ = 3, $$\mu $$ = 1

PREVIOUS NEXT

WB JEE Subjects