JEE Main & Advanced Mathematics Conic Sections Question Bank Self Evaluation Test - Conic Sections

  • question_answer
    If the latus rectum of an ellipse is equal to one half its minor axis, what is the eccentricity of the ellipse?

    A) \[\frac{1}{2}\]

    B) \[\frac{\sqrt{3}}{2}\]

    C) \[\frac{3}{4}\]

    D) \[\frac{\sqrt{15}}{4}\]

    Correct Answer: B

    Solution :

    [b] Length of latus rectum of an ellipse is \[\frac{2{{b}^{2}}}{a}\] Where b is semi minor axis and a is semi- major axis. As given, \[\frac{2{{b}^{2}}}{a}=b\] \[\Rightarrow 2b=a\Rightarrow \frac{b}{a}=\frac{1}{2}\] We know that eccentricity \[e=\sqrt{1-\frac{{{b}^{2}}}{{{a}^{2}}}}\] \[=\sqrt{1-\frac{1}{4}}=\frac{\sqrt{3}}{2}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner