Question

What is the angular magnification of a lens?

Answer 1

Angular magnification of a lens:

1. The ratio of the angle subtended at the eye by an image to the angle subtended at the eye by an object is known as the angular magnification of a lens.
2. Angular magnification of a lens, $A=\frac{{\theta }_i}{{\theta }_o}$.

Diagram:

1. In the diagram, an object is in front of the eye. The object makes an angle with the principle axis and the eye.
2. Also, the image makes an angle between the eye and the axis. (The image formed is in the retina and it is real.)
3. Thus, the angular magnification of a lens, $A=\frac{{\theta }_i}{{\theta }_o}$.
4. Where, ${\theta }_i$ is the angle subtended at the eye by an image, and ${\theta }_o$is the angle subtended at the eye by an object.