1
WB JEE 2020
MCQ (Single Correct Answer)
+2
-0.5
Change Language
If the vectors $$\alpha = \widehat i + a\widehat j + {a^2}\widehat k,\,\beta = \widehat i + b\widehat j + {b^2}\widehat k$$ and $$\,\gamma = \widehat i + c\widehat j + {c^2}\widehat k$$ are three non-coplanar

vectors and $$\left| {\matrix{ a & {{a^2}} & {1 + {a^3}} \cr b & {{b^2}} & {1 + {b^3}} \cr c & {{c^2}} & {1 + {c^3}} \cr } } \right| = 0$$, then the value of abc is
A
1
B
0
C
$$ - $$1
D
2
2
WB JEE 2019
MCQ (Single Correct Answer)
+1
-0.25
Change Language
Let A be a square matrix of order 3 whose all entries are 1 and let I3 be the identity matrix of order 3. Then, the matrix $$A - 3{I_3}$$ is
A
invertible
B
orthogonal
C
non-invertible
D
real Skew Symmetric matrix
3
WB JEE 2019
MCQ (Single Correct Answer)
+1
-0.25
Change Language
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
A
M
B
M'
C
null matrix
D
identity matrix
4
WB JEE 2019
MCQ (Single Correct Answer)
+1
-0.25
Change Language
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
A
$${1 \over 5}$$
B
5
C
52
D
1
WB JEE Subjects
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12