JEE Main202430 Jan 2024Morning ShiftMathematicsEllipseActual
If the length of the minor axis of ellipse is equal to half of the distance between the foci, then the eccentricity of the ellipse is :
Options
- A5 3
- B3 2
- C1 3
- D2 5
Correct answer
D. 2 5
Step-by-step solution
The length of minor axis is given by 2 b and the distance between foci is given by 2 a e Given: 2 b = 1 2 × 2 a e ⇒ 2 b = a e ⇒ 4 b 2 = a 2 e 2 ⇒ 4 b 2 a 2 = e 2 ⇒ 4 1 - e 2 = e 2 ⇒ 4 - 4 e 2 = e 2 ⇒ e = 2 5