Question

The graph drawn with object distance along abscissa and image distance along ordinate measuring the distance from the convex lens is :

• A. Straight line
• B. Parabola
• C. Circle
• D. A hyperbola

Answer 1

The correct option is D A hyperbola

In a convex lens, $\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$

Or $\frac{1}{v}-\frac{1}{f}=\frac{1}{u}$ where u is always negative and f is always positive.

$\frac{1}{v}=\frac{1}{f}-\frac{1}{u}$

So, as u is increased 1/u will decrease and $\frac{1}{f}-\frac{1}{u}$ will increase, so, $\frac{1}{v}$ increases or $v$ decreases.

So, its graph will be a hyperbola