Question

What is meant by magnification? Obtain the formula for finding magnification images formed by a mirror.

Answer 1

Here, we will be using the concept of magnification and the formula of magnification image formed by a mirror. The formula which represents the magnification image formed by a mirror is the ratio of height of object and the height of the object.

Complete step by step answer: The term magnification signifies the process of enlarging the apparent size not the physical size of the object to a quantified number to view clearly each part inside the object. The quantified number is known as the magnification. As this number is less than one means it refers to a reduction in size whereas as the number is greater than one then it is referred to as enlargement of the object (magnification).
The magnification is defined as the ratio of the height of the image formed by the mirror to the height of the object. The height of image formed by the mirror can be represented as ${h_{\;{\rm{i}}}}$and the height of the object as ${h_0}$ and the magnification would be represented by the symbol $m$ as$m = \dfrac{{{h_{\;{\rm{i}}}}}}{{{h_0}}}$. For the concave mirror the magnification formula can be represented as $m = \dfrac{{{h_{\;{\rm{i}}}}}}{{{h_0}}}$ or$m = - \dfrac{{{d_{\rm{i}}}}}{{{d_0}}}$ where ${d_0}$ represents the object distance and ${d_{\rm{i}}}$ is the image distance.

Note: In these type of problems one thing should be remember that ${d_{\rm{i}}}$ is positive if the image is a real image and located on the object’s side of the mirror and ${d_{\rm{i}}}$ would be negative if the image is a virtual image and located behind the mirror where as ${h_{\;{\rm{i}}}}$ is positive if the image is an upright image (virtual) and also ${h_{\;{\rm{i}}}}$ is negative if the image would be an inverted image (also real).