Intersection of a line and a parabola - class-XI

Intersection of a line and a parabola

12 Questions Published

Questions

Question 1 Multiple Choice (Single Answer)

The length of the chord of the parabola $y^2 = 4x$ which passes through the vertex and makes $30^o$ angle with x-axis is

  1. $\dfrac{\sqrt{3}}{2}$
  2. $\dfrac{3}{2}$
  3. $8\sqrt{3}$
  4. $\sqrt{3}$
Question 2 Multiple Choice (Single Answer)

Length of chord of parabola ${y}^{2}=4ax$ whose equation is $y-\sqrt {2}x+4\sqrt {2}a=0$

  1. $2\sqrt {11}a$
  2. $4\sqrt {2}a$
  3. $8\sqrt {2}a$
  4. $6\sqrt {3}a$
Question 3 Multiple Choice (Single Answer)

The length of the chord $y = x - 2$ intercepted by the parabola ${ y }^{ 2 }=4(x-1)$ is 

  1. $4$
  2. $\dfrac { 16 }{ 3 } $
  3. $\dfrac { 3 }{ 16 } $
  4. $\dfrac { 1 }{ 4 } $
Question 4 Multiple Choice (Single Answer)

The length of normal chord to the parabola $y^{2} = 4x$ which subtends a right angle at the vertex is

  1. $6\sqrt {3}$
  2. $6\sqrt {2}$
  3. $7\sqrt {2}$
  4. $7\sqrt {3}$
Question 5 Multiple Choice (Single Answer)

The number of focal chord(s) of length $\dfrac{4}{7}$ in the parabola $7y^2 = 8x$ is

  1. $1$
  2. $0$
  3. infinite
  4. none of these
Question 6 Multiple Choice (Single Answer)

Find the length of the chord of the parabola $y^2, =, 8x$, whose equation is $x + y = 1$.

  1. $8 \sqrt{3}$
  2. $4 \sqrt {3}$
  3. $2 \sqrt {3}$
  4. $\sqrt {3}$
Question 7 Multiple Choice (Single Answer)

The length of the chord of the parabola $x^2 = 4y $ passing through the vertex and having slope $cot \alpha $ is 

  1. $4 \cos \alpha . cosec^2\alpha$
  2. $ 4a \tan \alpha \sec \alpha $
  3. $4 \sin \alpha . \sec^2 \alpha $
  4. none of these
Question 8 Multiple Choice (Single Answer)

Let $AB$ be a chord of the parabola $y^{2}=4ax$.If the pole of $AB$ with respect to the parabola be $\left ( 2a,3a \right )$ then the length of $AB$ is 

  1. $\sqrt{13}a$
  2. $4a$
  3. $5a$
  4. $2\sqrt{3}a$
Question 9 Multiple Choice (Single Answer)

The condition that the straight line $\displaystyle lx + my + n = 0$ touches the parabola $\displaystyle x^2 = 4ay$ is

  1. $\displaystyle bn = am^2$
  2. $\displaystyle al^2 - mn = 0$
  3. $\displaystyle ln = am^2$
  4. $\displaystyle am = ln^2$
Question 10 Multiple Choice (Single Answer)

The length of the chord of the parabola $y^2 = x$ which is bisected at the point $(2, 1)$ is

  1. $2 \sqrt{3}$
  2. $4 \sqrt{3}$
  3. $3 \sqrt{2}$
  4. $2 \sqrt{5}$
Question 11 Multiple Choice (Single Answer)

If $2$ and $3$ are the length of the segments of any focal chord of a parabola $y^2 = 4ax$, then value of $2a$ is

  1. $\dfrac{13}{5}$
  2. $\dfrac{12}{5}$
  3. $\dfrac{11}{5}$
  4. none of these
Question 12 Multiple Choice (Single Answer)

If the line $y- \sqrt x +3 = 0$ cuts the parabola $y^2 = x + 2$ at $A$ and $B$, and if $P$ $(3,\ 0)$, then $PA.PB$ is equal to

  1. $\dfrac{2(\sqrt 3+2)}{3}$
  2. $\dfrac{4\sqrt 3}{2}$
  3. $\dfrac{4(2-\sqrt 3)}{3}$
  4. $\dfrac{4(\sqrt3+2)}{3}$