1
JEE Main 2019 (Online) 12th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
If A is a symmetric matrix and B is a skew-symmetric matrix such that A + B = $$\left[ {\matrix{ 2 & 3 \cr 5 & { - 1} \cr } } \right]$$, then AB is equal to :
A
$$\left[ {\matrix{ 4 & { - 2} \cr 1 & { - 4} \cr } } \right]$$
B
$$\left[ {\matrix{ { - 4} & { - 2} \cr { - 1} & 4 \cr } } \right]$$
C
$$\left[ {\matrix{ { - 4} & 2 \cr 1 & 4 \cr } } \right]$$
D
$$\left[ {\matrix{ 4 & { - 2} \cr { - 1} & { - 4} \cr } } \right]$$
2
JEE Main 2019 (Online) 12th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Let $$\overrightarrow a = 3\widehat i + 2\widehat j + 2\widehat k$$ and $$\overrightarrow b = \widehat i + 2\widehat j - 2\widehat k$$ be two vectors. If a vector perpendicular to both the vectors $$\overrightarrow a + \overrightarrow b $$ and $$\overrightarrow a - \overrightarrow b $$ has the magnitude 12 then one such vector is :
A
$$4\left( {2\widehat i - 2\widehat j - \widehat k} \right)$$
B
$$4\left( { - 2\widehat i - 2\widehat j + \widehat k} \right)$$
C
$$4\left( {2\widehat i + 2\widehat j + \widehat k} \right)$$
D
$$4\left( {2\widehat i + 2\widehat j - \widehat k} \right)$$
3
JEE Main 2019 (Online) 12th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
If $$B = \left[ {\matrix{ 5 & {2\alpha } & 1 \cr 0 & 2 & 1 \cr \alpha & 3 & { - 1} \cr } } \right]$$ is the inverse of a 3 × 3 matrix A, then the sum of all values of $$\alpha $$ for which det(A) + 1 = 0, is :
A
2
B
- 1
C
0
D
1
4
JEE Main 2019 (Online) 12th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A 2 m ladder leans against a vertical wall. If the top of the ladder begins to slide down the wall at the rate 25 cm/sec, then the rate (in cm/sec.) at which the bottom of the ladder slides away from the wall on the horizontal ground when the top of the ladder is 1 m above the ground is :
A
$${{25} \over 3}$$
B
25
C
25$$\sqrt 3 $$
D
$${{25} \over {\sqrt 3 }}$$
JEE Main Papers
2023
2021
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
CBSE
Class 12