Question

If the distance from the directrix is 5 units and the distance from the focus is 3 units then what is the value of eccentricity?

(a) 1.667

(b) 0.833

(c) 0.60

(d) 0.667

I had been asked this question in an interview for internship.

I'm obligated to ask this question of Basics of Conic Sections topic in section Curves used in Engineering Practice of Engineering Drawing

Answer 1

The correct answer is (c) 0.60

The best I can explain: Eccentricity is defined as the ratio of the distance from the focus to the distance from the directrix and it is denoted by e. Therefore, by definition, e = 3 ÷ 5 = 0.6. Hence the conic section is called an ellipse.