If $3\stackrel{^}{\mathrm{i}}+2\stackrel{^}{\mathrm{j}}+8\stackrel{^}{\mathrm{k}}$ and $2\stackrel{^}{\mathrm{i}}+\mathrm{x}\stackrel{^}{\mathrm{j}}+\stackrel{^}{\mathrm{k}}$ are at right angle then x=

(A)  7

(B)  -7

(C)  5

(D)  -4

Concept Questions :-

Scalar Product

Difficulty Level:

If a, b, c are three non-zero vectors such that $\stackrel{\to }{\mathrm{a}}+\stackrel{\to }{\mathrm{b}}+\stackrel{\to }{\mathrm{c}}=0$ the value of $\stackrel{\to }{\mathrm{a}}.\stackrel{\to }{\mathrm{b}}+\stackrel{\to }{\mathrm{b}}.\stackrel{\to }{\mathrm{c}}+\stackrel{\to }{\mathrm{c}}.\stackrel{\to }{\mathrm{a}}$ is

(A)  Less than zero

(B)  equal to zero

(C)  greater than zero

(D)  3

Concept Questions :-

Scalar Product
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Let  be distinct real numbers. The points with position vectors

(A)  are collinear

(B)  from an equilateral triangle

(C) form an isosceles triangle

(D)  from a right angled triangle

Concept Questions :-

Resultant of Vectors

Difficulty Level:

Two vectors $\stackrel{\to }{\mathrm{a}}$ and $\stackrel{\to }{\mathrm{b}}$ inclined at an angle $\mathrm{\theta }$ w.r.t. each other have a resultant $\stackrel{\to }{\mathrm{c}}$ which makes an angle $\mathrm{\beta }$ with $\stackrel{\to }{\mathrm{a}}$. If the directions of $\stackrel{\to }{\mathrm{a}}$ and $\stackrel{\to }{\mathrm{b}}$ are interchanged, then the resultant will have the same

(A)  magnitude

(B)  direction

(C)  magnitude as well as direction

(D)  neither magnitude nor direction

Difficulty Level:

Two vectors $\stackrel{\to }{\mathrm{A}}$ and $\stackrel{\to }{\mathrm{B}}$ lie in a plane. Another vector $\stackrel{\to }{\mathrm{C}}$ lies outside this plane. The resultant $\stackrel{\to }{\mathrm{A}}+\stackrel{\to }{\mathrm{B}}+\stackrel{\to }{\mathrm{C}}$ of these three vectors

(A)  can be zero

(B)  cannot be zero

(C)  lies in the plane of

(D)  lies in the plane of

Concept Questions :-

Resultant of Vectors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The vector sum of the forces of 10 N and 6 N can be

(A)  2 N

(B)  8 N

(C)  18 N

(D)  20 N

Concept Questions :-

Resultant of Vectors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A set of vectors taken in a given order gives a closed polygon. Then the resultant of these vectors is a

(A)  scalar quantity

(B)  pseudovector

(C)  unit vector

(D)  null vector

Concept Questions :-

Resultant of Vectors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The vector sum of two P and Q is minimum when the angle $\mathrm{\theta }$ between their positive directions, is

(A)  $\frac{\mathrm{\pi }}{4}$

(B)  $\frac{\mathrm{\pi }}{3}$

(C)  $\frac{\mathrm{\pi }}{2}$

(D)  $\mathrm{\pi }$

Concept Questions :-

Resultant of Vectors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The vector sum of two vectors $\stackrel{\to }{\mathrm{A}}$ and $\stackrel{\to }{\mathrm{B}}$ is maximum, then the angle $\mathrm{\theta }$ between two vectors is -

(A)  $0°$

(B)  $30°$

(C)  $45°$

(D)  $60°$

Concept Questions :-

Resultant of Vectors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Given: $\stackrel{\to }{\mathrm{C}}=\stackrel{\to }{\mathrm{A}}+\stackrel{\to }{\mathrm{B}}$. Also, the magnitude of  and $\stackrel{\to }{\mathrm{C}}$ are 12, 5 and 13 units respectively. The angle between $\stackrel{\to }{\mathrm{A}}$ and $\stackrel{\to }{\mathrm{B}}$ is

(A)  $0°$

(B)  $\frac{\mathrm{\pi }}{4}$

(C)  $\frac{\mathrm{\pi }}{2}$

(D)  $\mathrm{\pi }$

Concept Questions :-

Resultant of Vectors