Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If the latus rectum of an ellipse is equal to one half its minor axis, what is the eccentricity of the ellipse?
MathematicsEllipseNDANDA 2006 (Phase 1)
Options:
  • A $\frac{1}{2}$
  • B $\frac{\sqrt{3}}{2}$
  • C $\frac{3}{4}$
  • D $\frac{\sqrt{15}}{4}$
Solution:
1437 Upvotes Verified Answer
The correct answer is: $\frac{\sqrt{3}}{2}$
Length of latus rectum of an ellipse is $\frac{2 \mathrm{~b}^{2}}{\mathrm{a}}$ where bis
semi minor axis and a is semi-major axis. As given, $\frac{2 b^{2}}{a}=b$
$\Rightarrow 2 \mathrm{~b}=\mathrm{a} \Rightarrow \frac{\mathrm{b}}{\mathrm{a}}=\frac{1}{2}$
Weknow that eccentricity $\mathrm{e}=\sqrt{1-\frac{\mathrm{b}^{2}}{\mathrm{a}^{2}}}=\sqrt{1-\frac{1}{4}}=\frac{\sqrt{3}}{2}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.