An ellipse has its center at (1,−2), one focus at (3,−2) and one vertex at (5,−2). Then the length of its latus rectum is :
(A)316
(B)6✓ Correct
(C)43
(D)63
Answer: (B)
Solution
The centre (1,−2), focus (3,−2) and vertex (5,−2) all lie on y=−2, so the major axis is horizontal. The semi-major axis is a=∣5−1∣=4 and the centre-to-focus distance is ae=∣3−1∣=2, giving e=21. Then b2=a2(1−e2)=16(1−41)=12. The length of the latus rectum is
a2b2=42⋅12=6.
The length of the latus rectum is 6.
JEE Main · 2026 · 28 Jan 2026 · Shift 2 · Single correct option