Intersection of a line and a parabola - class-XI
Intersection of a line and a parabola
Questions
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
- $\dfrac{\sqrt{3}}{2}$
- $\dfrac{3}{2}$
- $8\sqrt{3}$
- $\sqrt{3}$
Length of chord of parabola ${y}^{2}=4ax$ whose equation is $y-\sqrt {2}x+4\sqrt {2}a=0$
- $2\sqrt {11}a$
- $4\sqrt {2}a$
- $8\sqrt {2}a$
- $6\sqrt {3}a$
The length of the chord $y = x - 2$ intercepted by the parabola ${ y }^{ 2 }=4(x-1)$ is
- $4$
- $\dfrac { 16 }{ 3 } $
- $\dfrac { 3 }{ 16 } $
- $\dfrac { 1 }{ 4 } $
The length of normal chord to the parabola $y^{2} = 4x$ which subtends a right angle at the vertex is
- $6\sqrt {3}$
- $6\sqrt {2}$
- $7\sqrt {2}$
- $7\sqrt {3}$
The number of focal chord(s) of length $\dfrac{4}{7}$ in the parabola $7y^2 = 8x$ is
- $1$
- $0$
- infinite
- none of these
Find the length of the chord of the parabola $y^2, =, 8x$, whose equation is $x + y = 1$.
- $8 \sqrt{3}$
- $4 \sqrt {3}$
- $2 \sqrt {3}$
- $\sqrt {3}$
The length of the chord of the parabola $x^2 = 4y $ passing through the vertex and having slope $cot \alpha $ is
- $4 \cos \alpha . cosec^2\alpha$
- $ 4a \tan \alpha \sec \alpha $
- $4 \sin \alpha . \sec^2 \alpha $
- none of these
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
- $\sqrt{13}a$
- $4a$
- $5a$
- $2\sqrt{3}a$
The condition that the straight line $\displaystyle lx + my + n = 0$ touches the parabola $\displaystyle x^2 = 4ay$ is
- $\displaystyle bn = am^2$
- $\displaystyle al^2 - mn = 0$
- $\displaystyle ln = am^2$
- $\displaystyle am = ln^2$
The length of the chord of the parabola $y^2 = x$ which is bisected at the point $(2, 1)$ is
- $2 \sqrt{3}$
- $4 \sqrt{3}$
- $3 \sqrt{2}$
- $2 \sqrt{5}$
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
- $\dfrac{13}{5}$
- $\dfrac{12}{5}$
- $\dfrac{11}{5}$
- none of these
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
- $\dfrac{2(\sqrt 3+2)}{3}$
- $\dfrac{4\sqrt 3}{2}$
- $\dfrac{4(2-\sqrt 3)}{3}$
- $\dfrac{4(\sqrt3+2)}{3}$