Basic Mathematics

127 Questions Start Allen Test
Q101 Allen 9. CROSS PRODUCT MCQ
Which of the following vector identities is false?
A.
$\vec{P} + \vec{Q} = \vec{Q} + \vec{P}$
B.
$\vec{P} \times \vec{Q} = \vec{Q} \times \vec{P}$
C.
$\vec{P}. \vec{Q} = \vec{Q}. \vec{P}$
D.
$\vec{P} \times \vec{Q} = -(\vec{Q} \times \vec{P})$
Q102 Allen 9. CROSS PRODUCT MCQ
What is the value of $\left(\vec{\mathrm{A}} +\vec{\mathrm{B}}\right)\times \left(\vec{\mathrm{A}} -\vec{\mathrm{B}}\right)$ ?
A.
$-2(\vec{\mathrm{A}}\times \vec{\mathrm{B}})$
B.
$2(\vec{\mathrm{B}}\times \vec{\mathrm{A}})$
C.
$\vec{0}$
D.
both 1 and 2
Q103 Allen 9. CROSS PRODUCT MCQ
The angle between vectors $(\vec{A} \times \vec{B})$ and $-(\vec{B} \times \vec{A})$ is:
A.
$\pi$ rad
B.
$\frac{\pi}{2}$ rad
C.
$\frac{\pi}{4}$ rad
D.
zero
Q104 Allen 9. CROSS PRODUCT MCQ
A vector $\vec{A}$ points vertically upward and $\vec{B}$ points towards south. The vector product $\vec{A} \times \vec{B}$ is
A.
zero
B.
along west
C.
along east
D.
vertically downward
Q105 Allen 9. CROSS PRODUCT MCQ
If $\frac{3}{4}|\vec{A}\times\vec{B}|=|\vec{A}.\vec{B}|$ , then the angle between $\vec{A}$ and $\vec{B}$ will be:
A.
$30^{\circ}$
B.
$45^{\circ}$
C.
$60^{\circ}$
D.
$53^{\circ}$
Q106 Allen 9. CROSS PRODUCT MCQ
If $\vec{A} = 3\hat{\mathrm{i}} +4\hat{\mathrm{j}}$ and $\vec{B} = 6\hat{\mathrm{i}} +8\hat{\mathrm{j}}$ and A and B are the magnitudes of $\vec{A}$ and $\vec{B}$ , then which of the following is true?
A.
$\vec{A}\times \vec{B} = \vec{0}$
B.
$\frac{A}{B} = 2$
C.
$\vec{A}.\vec{B} = 48$
D.
$A = 10$
Q107 Allen 9. CROSS PRODUCT MCQ
Two non zero vectors $\vec{A}$ and $\vec{B}$ are such that $\left|\vec{A}+\vec{B}\right|=\left|\vec{A}-\vec{B}\right|$ . Then select correct alternative
A.
$\vec{A}.\vec{B}=0$
B.
$\vec{A}\times\vec{B}=\vec{0}$
C.
$\vec{A}=\vec{0}$
D.
$\vec{B}=\vec{0}$
Q108 Allen 9. CROSS PRODUCT MCQ
A vector $\vec{\mathrm{F}}_1$ is along the positive Y-axis. If its vector product with another vector $\vec{\mathrm{F}}_2$ is zero then $\vec{\mathrm{F}}_2$ may be :-
A.
$4\hat{\mathrm{j}}$
B.
$-(i + \hat{j})$
C.
$(i + \hat{k})$
D.
$-4\hat{i}$
Q109 Allen 9. CROSS PRODUCT MCQ
If $\vec{A} \times \vec{B} = \vec{0}$ and $\vec{B} \times \vec{C} = \vec{0}$ , then the angle between $\vec{A}$ and $\vec{C}$ may be:
A.
$\pi$
B.
$\frac{\pi}{4}$
C.
$\frac{\pi}{2}$
D.
None
Q110 Allen 9. CROSS PRODUCT MCQ
The vector $\vec{B}=6\hat{i}+2\hat{j}+S\hat{k}$ is parallel to the vector $\vec{A}=3\hat{i}+\hat{j}+2\hat{k}$ if S=
A.
1
B.
4
C.
6
D.
8
Q111 Allen 9. CROSS PRODUCT MCQ
If three vectors satisfy the relation $\vec{A}.\vec{B}=0$ and $\vec{A}.\vec{C}=0$ , then $\vec{A}$ can be parallel to
A.
$\vec{C}$
B.
$\vec{B}$
C.
$\vec{B}\times\vec{C}$
D.
$\vec{B}.\vec{C}$
Q112 Allen 9. CROSS PRODUCT MCQ
For a body, angular velocity $\vec{\omega} = \hat{\mathrm{i}} - \hat{\mathrm{j}} + \hat{\mathrm{k}}$ and radius vector $\vec{r} = \hat{\mathrm{i}} + \hat{\mathrm{j}} + \hat{\mathrm{k}}$ , then its velocity $(\vec{v} = \vec{\omega} \times \vec{r})$ is:
A.
$-5\hat{\mathrm{i}} + 2\hat{\mathrm{j}} + 3\hat{\mathrm{k}}$
B.
$-5\hat{\mathrm{i}} + 2\hat{\mathrm{j}} + 3\hat{\mathrm{k}}$
C.
$-2\hat{\mathrm{i}} + 2\hat{\mathrm{k}}$
D.
$-5\hat{\mathrm{i}} - 2\hat{\mathrm{j}} - 3\hat{\mathrm{k}}$
Q113 Allen 9. CROSS PRODUCT MCQ
Find unit vector perpendicular to the plane of $\vec{a} = 2\hat{i} - 2\hat{j} +\hat{k}$ and $\vec{b} = \hat{i} +2\hat{j} +2\hat{k}$
A.
$\frac{2}{3}\hat{\mathrm{i}} +\frac{1}{3}\hat{\mathrm{j}} +\frac{2}{3}\hat{\mathrm{k}}$
B.
$-\frac{2}{3}\hat{\mathrm{i}} -\frac{1}{3}\hat{\mathrm{j}} -\frac{2}{3}\hat{\mathrm{k}}$
C.
$-\frac{2}{3}\hat{\mathrm{i}} -\frac{1}{3}\hat{\mathrm{j}} +\frac{2}{3}\hat{\mathrm{k}}$
D.
$\frac{2}{3}\hat{\mathrm{i}} +\frac{2}{3}\hat{\mathrm{j}} -\frac{1}{3}\hat{\mathrm{k}}$
Q114 Allen 10. PYQ MCQ
If vectors $\vec{A} = \cos \omega t\hat{i} +\sin \omega t\hat{j}$ and $\vec{B} = \cos \frac{\omega t}{2}\hat{i} +\sin \frac{\omega t}{2}\hat{j}$ are functions of time, then the value of $t$ at which they are orthogonal to each other is:
A.
$t = 0$
B.
$t = \frac{\pi}{4\omega}$
C.
$t = \frac{\pi}{2\omega}$
D.
$t = \frac{\pi}{\omega}$
Q115 Allen 10. PYQ MCQ
If the magnitude of sum of two vectors is equal to the magnitude of difference of the two vectors, the angle between these vectors is :-
A.
$0^{\circ}$
B.
$90^{\circ}$
C.
$45^{\circ}$
D.
$180^{\circ}$
Q116 Allen 10. PYQ MCQ
A particle moving with velocity $\vec{V}$ is acted by three forces shown by the vector triangle PQR. The velocity of the particle will:
A.
increase
B.
decrease
C.
remain constant
D.
change according to the smallest force $\overrightarrow{QR}$
Q117 Allen 10. PYQ MCQ
If $\vec{\mathrm{F}} = 2\hat{\mathrm{i}} +\hat{\mathrm{j}} -\hat{\mathrm{k}}$ and $\vec{\mathrm{r}} = 3\hat{\mathrm{i}} +2\hat{\mathrm{j}} -2\hat{\mathrm{k}}$ , then the scalar and vector products of $\vec{\mathrm{F}}$ and $\vec{\mathrm{r}}$ have the magnitudes respectively as:
A.
$5,\sqrt{3}$
B.
$4,\sqrt{5}$
C.
$10,\sqrt{2}$
D.
$10,2$
Q118 Allen 11. ANALYTICAL QUESTIONS MCQ
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Current has magnitude as well as direction but still not considered as vector.
Reason (R): Current do not follow vector algebra.
In the light of the above statements,
choose the most appropriate answer from the options given below:
A.
Both (A) and (R) are true and (R) is the correct explanation of (A).
B.
Both (A) and (R) are true and (R) is NOT the correct explanation of (A).
C.
(A) is true but (R) is false.
D.
(A) is false but (R) is true.
Q119 Allen 11. ANALYTICAL QUESTIONS MCQ
Two vectors $\vec{A} \& \vec{B}$ have equal magnitude equal to $Z$ . If angle between $\vec{A} \& \vec{B}$ is $60^{\circ}$ then match the following: Match the Column-I with Column-II
Column-IColumn-II
(A)$|\vec{A}+\vec{B}|$
(B)$|\vec{A}-\vec{B}|$
(C)$\vec{A}\cdot\vec{B}$
(D)$|\vec{A}\times\vec{B}|$
(P)$\frac{\sqrt{3}}{2}Z^2$
(Q)$Z$
(R)$\sqrt{3}Z$
(S)None
A.
A-R, B-S, C-Q, D-P
B.
A-R, B-Q, C-S, D-P
C.
A-P, B-Q, C-R, D-S
D.
A-Q, B-P, C-S, D-P
Q120 Allen 11. ANALYTICAL QUESTIONS MCQ
Match the following
Column-IColumn-II
(A)$\vec{a} +\vec{b} = \vec{c}$
(B)$\vec{a}-\vec{c}=\vec{b}$
(C)$\vec{\mathbf{b}} -\vec{\mathbf{a}} = \vec{\mathbf{c}}$
(D)$\vec{a} +\vec{b} +\vec{c} = \vec{0}$
(P)
(Q)
(R)
(S)
A.
(A)-(S), (B)-(R), (C)-(P), (D)-(Q)
B.
(A)-(R), (B)-(S), (C)-(Q), (D)-(P)
C.
(A)-(P), (B)-(Q), (C)-(R), (D)-(S)
D.
(A)-(S), (B)-(R), (C)-(Q), (D)-(P)
Q121 Allen 11. ANALYTICAL QUESTIONS MCQ
Given below are two statements: Statement I : Resultant of 2 forces of magnitude 4N and 5N can be 2N in magnitude. Statement II: $\left|\vec{a}\right|-\left|\vec{b}\right|\leq\left|\vec{a}+\vec{b}\right|\leq\left|\vec{a}\right|+\left|\vec{b}\right|$ In the light of the above statements, choose the most appropriate answer from the options given below :
A.
Both statement I and statement II are correct.
B.
Statement I is correct and statement II is incorrect.
C.
Statement I is incorrect and statement II is correct.
D.
Both statements I and statements II are incorrect.
Q122 Allen 11. ANALYTICAL QUESTIONS MCQ
Given below are two statements : Statement I : Two null vector have same direction. Statement II: $\vec{A} \times \vec{B}$ lies in the plane of $\vec{A} + \vec{B}$ . In the light of the above statements, choose the most appropriate answer from the options given below:
A.
Both statement I and statement II are correct.
B.
Statement I is correct and statement II is incorrect.
C.
Statement I is incorrect and statement II is correct.
D.
Both statements I and statements II are incorrect.
Q123 Allen 11. ANALYTICAL QUESTIONS MCQ
Which of the following is correct :
(i) $\vec{A} \cdot \vec{B}$ is a vector quantity
(ii) $\vec{A} \times \vec{B}$ is perpendicular to plane of $\vec{A} + \vec{B}$
(iii) For two orthogonal vectors $\vec{A} \cdot \vec{B} = 0$
(iv) If vectors are parallel or antiparallel, then $\vec{A} \times \vec{B} = \vec{0}$
A.
(i) only
B.
(i) & (ii)
C.
(iii) & (iv) only
D.
(ii), (iii) & (iv)
Q124 Allen 11. ANALYTICAL QUESTIONS MCQ
Given below are two statements: Statement-I : For every small angle $\theta$ , we may use approximation $\sin\theta \approx \theta \approx \tan\theta$ . Statement-II : For very small angle $\theta$ , the hypotenuse and the base become approximately of the same length.
A.
Statement-I is true, Statement-II is true; Statement-II is a correct explanation for Statement-I.
B.
Statement-I is true, Statement-II is true; Statement-II is not a correct explanation for Statement-I.
C.
Statement-I is true, Statement-II is false.
D.
Statement-I is false, Statement-II is true.
Q125 Allen 11. ANALYTICAL QUESTIONS MCQ
Refer the given figure and identify correct statement(s)
(A) Distance of A from x-axis is $5\sqrt{3}$ cm.
(B) Distance of B from x-axis is 6 cm.
(C) Distance of A from y-axis is 5 cm.
(D) Distance of B from y-axis is 8 cm.
A.
A, C
B.
A, D
C.
A, B, C
D.
A, B, C, D