Correct Answer - Option 4 : 1, 2 and 3
CONCEPT:
Eccentricity:
The constant ratio of distance of point lying on conic from the focus to its perpendicular distance from directrix is called the eccentricity of a conic section and is denoted by e.
- For an ellipse: e < 1
- For a parabola: e = 1
- For a hyperbola: e > 1
- For a circle: e = 0
- For a pair of straight lines: e = ∞
CALCULATION:
As we know that, eccentricity of a circle is 0 i.e e = 0 for a circle.
So, statement 1 is correct.
We also know that, eccentricity of a parabola is equal to 1 i.e e = 1 for a parabola.
So, statement 2 is also correct.
We also know that, eccentricity of an ellipse is always less than 1 i.e e < 1 for an ellipse.
So, statement 3 is also correct.
Hence, correct option is 4.