Vector Algebra

38 Questions
2025 JEE Mains Numerical
JEE Main 2025 (Online) 23rd January Morning Shift

Two particles are located at equal distance from origin. The position vectors of those are represented by $\vec{A}=2 \hat{i}+3 n \hat{j}+2 \hat{k}$ and $\bar{B}=2 \hat{i}-2 \hat{j}+4 p \hat{k}$, respectively. If both the vectors are at right angle to each other, the value of $n^{-1}$ is ________ .

2024 JEE Mains Numerical
JEE Main 2024 (Online) 9th April Evening Shift

The resultant of two vectors $\vec{A}$ and $\vec{B}$ is perpendicular to $\vec{A}$ and its magnitude is half that of $\vec{B}$. The angle between vectors $\vec{A}$ and $\vec{B}$ is _________$^\circ$.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 9th April Morning Shift

If $\vec{a}$ and $\vec{b}$ makes an angle $\cos ^{-1}\left(\frac{5}{9}\right)$ with each other, then $|\vec{a}+\vec{b}|=\sqrt{2}|\vec{a}-\vec{b}|$ for $|\vec{a}|=n|\vec{b}|$ The integer value of $\mathrm{n}$ is _________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 8th April Morning Shift

Three vectors $\overrightarrow{\mathrm{OP}}, \overrightarrow{\mathrm{OQ}}$ and $\overrightarrow{\mathrm{OR}}$ each of magnitude $\mathrm{A}$ are acting as shown in figure. The resultant of the three vectors is $\mathrm{A} \sqrt{x}$. The value of $x$ is _________.

JEE Main 2024 (Online) 8th April Morning Shift Physics - Vector Algebra Question 4 English

2024 JEE Mains Numerical
JEE Main 2024 (Online) 6th April Morning Shift

For three vectors $\vec{A}=(-x \hat{i}-6 \hat{j}-2 \hat{k}), \vec{B}=(-\hat{i}+4 \hat{j}+3 \hat{k})$ and $\vec{C}=(-8 \hat{i}-\hat{j}+3 \hat{k})$, if $\vec{A} \cdot(\vec{B} \times \vec{C})=0$, then value of $x$ is ________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 30th January Evening Shift

A vector has magnitude same as that of $\vec{A}=3 \hat{i}+4 \hat{j}$ and is parallel to $\vec{B}=4 \hat{i}+3 \hat{j}$. The $x$ and $y$ components of this vector in first quadrant are $x$ and 3 respectively where $x=$ _________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 25th January Morning Shift

If $\overrightarrow P = 3\widehat i + \sqrt 3 \widehat j + 2\widehat k$ and $\overrightarrow Q = 4\widehat i + \sqrt 3 \widehat j + 2.5\widehat k$ then, the unit vector in the direction of $\overrightarrow P \times \overrightarrow Q $ is ${1 \over x}\left( {\sqrt 3 \widehat i + \widehat j - 2\sqrt 3 \widehat k} \right)$. The value of $x$ is _________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 24th January Morning Shift

Vectors $a\widehat i + b\widehat j + \widehat k$ and $2\widehat i - 3\widehat j + 4\widehat k$ are perpendicular to each other when $3a + 2b = 7$, the ratio of $a$ to $b$ is ${x \over 2}$. The value of $x$ is ____________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 28th July Morning Shift

If the projection of $2 \hat{i}+4 \hat{j}-2 \hat{k}$ on $\hat{i}+2 \hat{j}+\alpha \hat{k}$ is zero. Then, the value of $\alpha$ will be ___________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 26th July Evening Shift

If $\vec{A}=(2 \hat{i}+3 \hat{j}-\hat{k})\, \mathrm{m}$ and $\vec{B}=(\hat{i}+2 \hat{j}+2 \hat{k}) \,\mathrm{m}$. The magnitude of component of vector $\vec{A}$ along vector $\vec{B}$ will be ____________ $\mathrm{m}$.

2021 JEE Mains Numerical
JEE Main 2021 (Online) 22th July Evening Shift
Three particles P, Q and R are moving along the vectors $\overrightarrow A = \widehat i + \widehat j$, $\overrightarrow B = \widehat j + \widehat k$ and $\overrightarrow C = - \widehat i + \widehat j$ respectively. They strike on a point and start to move in different directions. Now particle P is moving normal to the plane which contains vector $\overrightarrow A $ and $\overrightarrow B $. Similarly particle Q is moving normal to the plane which contains vector $\overrightarrow A $ and $\overrightarrow C $. The angle between the direction of motion of P and Q is ${\cos ^{ - 1}}\left( {{1 \over {\sqrt x }}} \right)$. Then the value of x is _______________.
2021 JEE Mains Numerical
JEE Main 2021 (Online) 25th February Evening Shift
If $\overrightarrow P \times \overrightarrow Q = \overrightarrow Q \times \overrightarrow P $, the angle between $\overrightarrow P $ and $\overrightarrow Q $ is $\theta$(0$^\circ$ < $\theta$ < 360$^\circ$). The value of '$\theta$' will be ___________$^\circ$.
2020 JEE Mains Numerical
JEE Main 2020 (Online) 7th January Evening Slot
The sum of two forces $\overrightarrow P $ and $\overrightarrow Q $ is $\overrightarrow R $ such that $\left| {\overrightarrow R } \right| = \left| {\overrightarrow P } \right|$ . The angle $\theta $ (in degrees) that the resultant of 2${\overrightarrow P }$ and ${\overrightarrow Q }$ will make with ${\overrightarrow Q }$ is , ..............
2024 JEE Mains MCQ
JEE Main 2024 (Online) 5th April Morning Shift

The angle between vector $\vec{Q}$ and the resultant of $(2 \vec{Q}+2 \vec{P})$ and $(2 \vec{Q}-2 \vec{P})$ is :

A.
$ \tan ^{-1}(\mathrm{P} / \mathrm{Q}) $
B.
0$^\circ$
C.
$ \tan ^{-1} \frac{(2 \vec{Q}-2 \vec{P})}{2 \vec{Q}+2 \vec{P}} $
D.
$ \tan ^{-1}(2 Q / \mathrm{P}) $
2024 JEE Mains MCQ
JEE Main 2024 (Online) 31st January Evening Shift

If two vectors $\vec{A}$ and $\vec{B}$ having equal magnitude $R$ are inclined at angle $\theta$, then

A.
$|\vec{A}+\vec{B}|=2 R \cos \left(\frac{\theta}{2}\right)$
B.
$|\vec{A}-\vec{B}|=2 R \cos \left(\frac{\theta}{2}\right)$
C.
$|\vec{A}-\vec{B}|=\sqrt{2} R \sin \left(\frac{\theta}{2}\right)$
D.
$|\vec{A}+\vec{B}|=2 R \sin \left(\frac{\theta}{2}\right)$
2023 JEE Mains MCQ
JEE Main 2023 (Online) 15th April Morning Shift
A vector in $x-y$ plane makes an angle of $30^{\circ}$ with $y$-axis. The magnitude of $\mathrm{y}$-component of vector is $2 \sqrt{3}$. The magnitude of $x$-component of the vector will be :
A.
$\sqrt{3}$
B.
2
C.
6
D.
$\frac{1}{\sqrt{3}}$
2023 JEE Mains MCQ
JEE Main 2023 (Online) 11th April Evening Shift

When vector $\vec{A}=2 \hat{i}+3 \hat{j}+2 \hat{k}$ is subtracted from vector $\overrightarrow{\mathrm{B}}$, it gives a vector equal to $2 \hat{j}$. Then the magnitude of vector $\overrightarrow{\mathrm{B}}$ will be :

A.
3
B.
$\sqrt{33}$
C.
$\sqrt6$
D.
$\sqrt5$
2023 JEE Mains MCQ
JEE Main 2023 (Online) 8th April Morning Shift

Two forces having magnitude $A$ and $\frac{A}{2}$ are perpendicular to each other. The magnitude of their resultant is:

A.
$\frac{5 A}{2}$
B.
$\frac{\sqrt{5} A}{4}$
C.
$\frac{\sqrt{5} A}{2}$
D.
$\frac{\sqrt{5} A^{2}}{2}$
2023 JEE Mains MCQ
JEE Main 2023 (Online) 24th January Evening Shift

If two vectors $\overrightarrow P = \widehat i + 2m\widehat j + m\widehat k$ and $\overrightarrow Q = 4\widehat i - 2\widehat j + m\widehat k$ are perpendicular to each other. Then, the value of m will be :

A.
$-1$
B.
3
C.
1
D.
2
2022 JEE Mains MCQ
JEE Main 2022 (Online) 29th June Morning Shift

Two vectors $\overrightarrow A $ and $\overrightarrow B $ have equal magnitudes. If magnitude of $\overrightarrow A $ + $\overrightarrow B $ is equal to two times the magnitude of $\overrightarrow A $ $-$ $\overrightarrow B $, then the angle between $\overrightarrow A $ and $\overrightarrow B $ will be :

A.
${\sin ^{ - 1}}\left( {{3 \over 5}} \right)$
B.
${\sin ^{ - 1}}\left( {{1 \over 3}} \right)$
C.
${\cos ^{ - 1}}\left( {{3 \over 5}} \right)$
D.
${\cos ^{ - 1}}\left( {{1 \over 3}} \right)$
2022 JEE Mains MCQ
JEE Main 2022 (Online) 25th June Morning Shift

$\overrightarrow A $ is a vector quantity such that $|\overrightarrow A |$ = non-zero constant. Which of the following expression is true for $\overrightarrow A $ ?

A.
$\overrightarrow A \,.\,\overrightarrow A = 0$
B.
$\overrightarrow A \times \overrightarrow A < 0$
C.
$\overrightarrow A \times \overrightarrow A = 0$
D.
$\overrightarrow A \times \overrightarrow A > 0$
2022 JEE Mains MCQ
JEE Main 2022 (Online) 25th June Morning Shift

Which of the following relations is true for two unit vector $\widehat A$ and $\widehat B$ making an angle $\theta$ to each other?

A.
$|\widehat A + \widehat B| = |\widehat A - \widehat B|\tan {\theta \over 2}$
B.
$|\widehat A - \widehat B| = |\widehat A + \widehat B|\tan {\theta \over 2}$
C.
$|\widehat A + \widehat B| = |\widehat A - \widehat B|cos{\theta \over 2}$
D.
$|\widehat A - \widehat B| = |\widehat A + \widehat B|\cos {\theta \over 2}$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 31st August Evening Shift
Statement I :

Two forces $\left( {\overrightarrow P + \overrightarrow Q } \right)$ and $\left( {\overrightarrow P - \overrightarrow Q } \right)$ where $\overrightarrow P \bot \overrightarrow Q $, when act at an angle $\theta$1 to each other, the magnitude of their resultant is $\sqrt {3({P^2} + {Q^2})} $, when they act at an angle $\theta$2, the magnitude of their resultant becomes $\sqrt {2({P^2} + {Q^2})} $. This is possible only when ${\theta _1} < {\theta _2}$.

Statement II :

In the situation given above.

$\theta$1 = 60$^\circ$ and $\theta$2 = 90$^\circ$

In the light of the above statements, choose the most appropriate answer from the options given below :-
A.
Statement I is false but Statement II is true
B.
Both Statement I and Statement II are true
C.
Statement I is true but Statement II is false
D.
Both Statement I and Statement II are false.
2021 JEE Mains MCQ
JEE Main 2021 (Online) 27th August Morning Shift
The resultant of these forces $\overrightarrow {OP} ,\overrightarrow {OQ} ,\overrightarrow {OR} ,\overrightarrow {OS} $ and $\overrightarrow {OT} $ is approximately .......... N.

[Take $\sqrt 3 = 1.7$, $\sqrt 2 = 1.4$ Given $\widehat i$ and $\widehat j$ unit vectors along x, y axis]

JEE Main 2021 (Online) 27th August Morning Shift Physics - Vector Algebra Question 21 English
A.
$9.25\widehat i + 5\widehat j$
B.
$3\widehat i + 15\widehat j$
C.
$2.5\widehat i - 14.5\widehat j$
D.
$ - 1.5\widehat i - 15.5\widehat j$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 26th August Evening Shift
The angle between vector $\left( {\overrightarrow A } \right)$ and $\left( {\overrightarrow A - \overrightarrow B } \right)$ is :

JEE Main 2021 (Online) 26th August Evening Shift Physics - Vector Algebra Question 22 English
A.
${\tan ^{ - 1}}\left( {{{ - {B \over 2}} \over {A - B{{\sqrt 3 } \over 2}}}} \right)$
B.
${\tan ^{ - 1}}\left( {{A \over {0.7B}}} \right)$
C.
${\tan ^{ - 1}}\left( {{{\sqrt 3 B} \over {2A - B}}} \right)$
D.
${\tan ^{ - 1}}\left( {{{B\cos \theta } \over {A - B\sin \theta }}} \right)$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 26th August Morning Shift
The magnitude of vectors $\overrightarrow {OA} $, $\overrightarrow {OB} $ and $\overrightarrow {OC} $ in the given figure are equal. The direction of $\overrightarrow {OA} $ + $\overrightarrow {OB} $ $-$ $\overrightarrow {OC} $ with x-axis will be :

JEE Main 2021 (Online) 26th August Morning Shift Physics - Vector Algebra Question 23 English
A.
${\tan ^{ - 1}}{{(1 - \sqrt 3 - \sqrt 2 )} \over {(1 + \sqrt 3 + \sqrt 2 )}}$
B.
${\tan ^{ - 1}}{{(\sqrt 3 - 1 + \sqrt 2 )} \over {(1 + \sqrt 3 - \sqrt 2 )}}$
C.
${\tan ^{ - 1}}{{(\sqrt 3 - 1 + \sqrt 2 )} \over {(1 - \sqrt 3 + \sqrt 2 )}}$
D.
${\tan ^{ - 1}}{{(1 + \sqrt 3 - \sqrt 2 )} \over {(1 - \sqrt 3 - \sqrt 2 )}}$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 27th July Morning Shift
Assertion A : If A, B, C, D are four points on a semi-circular are with centre at 'O' such that $\left| {\overrightarrow {AB} } \right| = \left| {\overrightarrow {BC} } \right| = \left| {\overrightarrow {CD} } \right|$, then $\overrightarrow {AB} + \overrightarrow {AC} + \overrightarrow {AD} = 4\overrightarrow {AO} + \overrightarrow {OB} + \overrightarrow {OC} $

Reason R : Polygon law of vector addition yields $\overrightarrow {AB} + \overrightarrow {BC} + \overrightarrow {CD} + \overrightarrow {AD} = 2\overrightarrow {AO} $

JEE Main 2021 (Online) 27th July Morning Shift Physics - Vector Algebra Question 24 English
In the light of the above statements, choose the most appropriate answer from the options given below :
A.
A is correct but R is not correct.
B.
A is not correct but R is correct.
C.
Both A and R are correct and R is the correct explanation of A.
D.
Both A and R are correct but R is not the correct explanation of A.
2021 JEE Mains MCQ
JEE Main 2021 (Online) 25th July Evening Shift
Two vectors $\overrightarrow X $ and $\overrightarrow Y $ have equal magnitude. The magnitude of ($\overrightarrow X $ $-$ $\overrightarrow Y $) is n times the magnitude of ($\overrightarrow X $ + $\overrightarrow Y $). The angle between $\overrightarrow X $ and $\overrightarrow Y $ is :
A.
${\cos ^{ - 1}}\left( {{{ - {n^2} - 1} \over {{n^2} - 1}}} \right)$
B.
${\cos ^{ - 1}}\left( {{{{n^2} - 1} \over { - {n^2} - 1}}} \right)$
C.
${\cos ^{ - 1}}\left( {{{{n^2} + 1} \over { - {n^2} - 1}}} \right)$
D.
${\cos ^{ - 1}}\left( {{{{n^2} + 1} \over {{n^2} - 1}}} \right)$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 25th July Morning Shift
Match List - I with List - II

JEE Main 2021 (Online) 25th July Morning Shift Physics - Vector Algebra Question 26 English
Choose the correct answer from the options given below :
A.
(a) $\to$ (iv), (b) $\to$ (i), (c) $\to$ (iii), (d) $\to$ (ii)
B.
(a) $\to$ (iv), (b) $\to$ (iii), (c) $\to$ (i), (d) $\to$ (ii)
C.
(a) $\to$ (iii), (b) $\to$ (ii), (c) $\to$ (iv), (d) $\to$ (i)
D.
(a) $\to$ (i), (b) $\to$ (iv), (c) $\to$ (ii), (d) $\to$ (iii)
2021 JEE Mains MCQ
JEE Main 2021 (Online) 22th July Evening Shift
What will be the projection of vector $\overrightarrow A = \widehat i + \widehat j + \widehat k$ on vector $\overrightarrow B = \widehat i + \widehat j$ ?
A.
$\sqrt 2 (\widehat i + \widehat j + \widehat k)$
B.
$(\widehat i + \widehat j)$
C.
$\sqrt 2 (\widehat i + \widehat j)$
D.
$2(\widehat i + \widehat j + \widehat k)$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 20th July Evening Shift
Two vectors ${\overrightarrow P }$ and ${\overrightarrow Q }$ have equal magnitudes. If the magnitude of ${\overrightarrow P + \overrightarrow Q }$ is n times the magnitude of ${\overrightarrow P - \overrightarrow Q }$, then angle between ${\overrightarrow P }$ and ${\overrightarrow Q }$ is :
A.
${\sin ^{ - 1}}\left( {{{n - 1} \over {n + 1}}} \right)$
B.
${\cos ^{ - 1}}\left( {{{n - 1} \over {n + 1}}} \right)$
C.
${\sin ^{ - 1}}\left( {{{{n^2} - 1} \over {{n^2} + 1}}} \right)$
D.
${\cos ^{ - 1}}\left( {{{{n^2} - 1} \over {{n^2} + 1}}} \right)$
2021 JEE Mains MCQ
JEE Main 2021 (Online) 20th July Morning Shift
If $\overrightarrow A $ and $\overrightarrow B $ are two vectors satisfying the relation $\overrightarrow A $ . $\overrightarrow B $ = $\left| {\overrightarrow A \times \overrightarrow B } \right|$. Then the value of $\left| {\overrightarrow A - \overrightarrow B } \right|$ will be :
A.
$\sqrt {{A^2} + {B^2} + \sqrt 2 AB} $
B.
$\sqrt {{A^2} + {B^2}} $
C.
$\sqrt {{A^2} + {B^2} - \sqrt 2 AB} $
D.
$\sqrt {{A^2} + {B^2} + 2AB} $
2021 JEE Mains MCQ
JEE Main 2021 (Online) 25th February Morning Shift
In an octagon ABCDEFGH of equal side, what is the sum of

$\overrightarrow {AB} + \overrightarrow {AC} + \overrightarrow {AD} + \overrightarrow {AE} + \overrightarrow {AF} + \overrightarrow {AG} + \overrightarrow {AH} $,

if, $\overrightarrow {AO} = 2\widehat i + 3\widehat j - 4\widehat k$

JEE Main 2021 (Online) 25th February Morning Shift Physics - Vector Algebra Question 32 English
A.
$ - 16\widehat i - 24\widehat j + 32\widehat k$
B.
$16\widehat i + 24\widehat j - 32\widehat k$
C.
$16\widehat i + 24\widehat j + 32\widehat k$
D.
$16\widehat i - 24\widehat j + 32\widehat k$
2019 JEE Mains MCQ
JEE Main 2019 (Online) 8th April Evening Slot
Let $\left| {\mathop {{A_1}}\limits^ \to } \right| = 3$, $\left| {\mathop {{A_2}}\limits^ \to } \right| = 5$ and $\left| {\mathop {{A_1}}\limits^ \to + \mathop {{A_2}}\limits^ \to } \right| = 5$. The value of $\left( {2\mathop {{A_1}}\limits^ \to + 3\mathop {{A_2}}\limits^ \to } \right)\left( {3\mathop {{A_1}}\limits^ \to - \mathop {2{A_2}}\limits^ \to } \right)$ is :-
A.
–118.5
B.
–112.5
C.
–99.5
D.
–106.5
2019 JEE Mains MCQ
JEE Main 2019 (Online) 10th January Evening Slot
Two vectors $\overrightarrow A $ and $\overrightarrow B $ have equal magnitudes. The magnitude of $\left( {\overrightarrow A + \overrightarrow B } \right)$ is 'n' times the magnitude of $\left( {\overrightarrow A - \overrightarrow B } \right)$ . The angle between ${\overrightarrow A }$ and ${\overrightarrow B }$ is -
A.
${\sin ^{ - 1}}\left[ {{{n - 1} \over {n + 1}}} \right]$
B.
${\sin ^{ - 1}}\left[ {{{{n^2} - 1} \over {{n^2} + 1}}} \right]$
C.
${\cos ^{ - 1}}\left[ {{{{n^2} - 1} \over {{n^2} + 1}}} \right]$
D.
${\cos ^{ - 1}}\left[ {{{n - 1} \over {n + 1}}} \right]$
2019 JEE Mains MCQ
JEE Main 2019 (Online) 10th January Morning Slot
In the cube of side ‘a’ shown in the figure, the vector from the central point of the face ABOD to the central point of the face BEFO will be -

JEE Main 2019 (Online) 10th January Morning Slot Physics - Vector Algebra Question 36 English
A.
${1 \over 2}a\left( {\widehat k - \widehat i} \right)$
B.
${1 \over 2}a\left( {\widehat j - \widehat i} \right)$
C.
${1 \over 2}a\left( {\widehat j - \widehat k} \right)$
D.
${1 \over 2}a\left( {\widehat i - \widehat k} \right)$
2018 JEE Mains MCQ
JEE Main 2018 (Online) 16th April Morning Slot
Let $\overrightarrow A $ = $\left( {\widehat i + \widehat j} \right)$ and, $\overrightarrow B = \left( {2\widehat i - \widehat j} \right).$ The magnitude of a coplanar vector $\overrightarrow C $ such that $\overrightarrow A .\overrightarrow C = \overrightarrow B .\overrightarrow C = \overrightarrow A .\overrightarrow B ,$ is given by :
A.
$\sqrt {{{10} \over 9}} $
B.
$\sqrt {{{5} \over 9}} $
C.
$\sqrt {{{20} \over 9}} $
D.
$\sqrt {{{9} \over 12}} $
2004 JEE Mains MCQ
AIEEE 2004
If $\overrightarrow A \times \overrightarrow B = \overrightarrow B \times \overrightarrow A $, then the angle beetween A and B is
A.
${\pi \over 2}$
B.
${\pi \over 3}$
C.
$\pi $
D.
${\pi \over 4}$