The maximum value of $7+6\mathrm{x}-9{\mathrm{x}}^{2}$ is

(A)  8

(B)  -8

(C)  4

(D)  -4

Concept Questions :-

Differentiation
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

If $\mathrm{f}\left(\mathrm{x}\right)={\mathrm{x}}^{2}-2\mathrm{x}+4$, then f(x) has

1.  a minimum at x=1

2.  a maximum at x=1

3.  no extreme point

4.  no minimum

Concept Questions :-

Differentiation
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A particle is moving along x-axis. The velocity v of particle varies with its position x as $\mathrm{v}=\frac{1}{\mathrm{x}}$. Find velocity of particle as a function of time t given that at t=0, x=1 .

1.  $\mathrm{v}=\sqrt{2\mathrm{t}+1}$

2.  $\mathrm{v}=\frac{1}{\sqrt{2\mathrm{t}+1}}$

3.  $\mathrm{v}=\frac{1}{\mathrm{t}}$

4.  None of these

Concept Questions :-

Integration
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A vector $\stackrel{\to }{\mathrm{A}}$ is directed along $30°$ west of north direction and another vector $\stackrel{\to }{\mathrm{B}}$ along $15°$ south of east. Their resultant cannot be in ____________ direction.

(A)  North

(B)  East

(C)  North-East

(D)  South

Concept Questions :-

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

Difficulty Level:

ABCD is a quadrilateral. Forces  act at a point. Their resultant is

(A)

(B)

(C)  zero vector

(D)

Concept Questions :-

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

Difficulty Level:

The resultant of the forces $\stackrel{\to }{\mathrm{P}}$ and $\stackrel{\to }{\mathrm{Q}}$ is $\stackrel{\to }{\mathrm{R}}$. If $\stackrel{\to }{\mathrm{Q}}$ is double then the resultant also doubles in magnitude. Find the angle between $\stackrel{\to }{\mathrm{P}}$ and $\stackrel{\to }{\mathrm{Q}}$.

(A)

(B)

(C)

(D)

Concept Questions :-

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

Difficulty Level:

The maximum and minimum magnitude of the resultant of two vectors are 17 units and 7 units respectively. Then the magnitude of resultant of the vectors when they act perpendicular to each other is:

(A)  14

(B)  16

(C)  18

(D)  13

Concept Questions :-

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

Difficulty Level:

A vector $\stackrel{\to }{\mathrm{A}}$ makes an angle of $20°$ and $\stackrel{\to }{\mathrm{B}}$ makes an angle of $110°$ with the X-axis. The magnitudes of these vectors are 3 m and 4 m respectively. Find the magnitude of the resultant.

(A)  $1$

(B)  $5\sqrt{2}$

(C)  $5$

(D)  $7$

Concept Questions :-

Resultant of Vectors

Difficulty Level:

A particle is moving westward with a velocity  Its velocity changed to ${\stackrel{\to }{\mathrm{v}}}_{2}=5\mathrm{m}/\mathrm{s}$ northward. The change in velocity vector $\left(∆\stackrel{\to }{\mathrm{V}}={\stackrel{\to }{\mathrm{v}}}_{2}-{\stackrel{\to }{\mathrm{v}}}_{1}\right)$ is:

(A)   towards north east

(B)   towards north west

(C)  zero

(D)  towards north west

Concept Questions :-

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

Difficulty Level:

Consider east as positive x-axis, north as positive y-axis and vertically upward direction as z-axis. A helicopter first rises up to an altitude of 100 m than flies straight in north 500 m and then suddenly takes a turn towards east and travels 1000 m east. What is position vector of helicopter. (Take starting point as origin)

(A)

(B)

(C)

(D)

Concept Questions :-

Resultant of Vectors