MAGNIFICATION

Magnification is the increase in the image size produced by spherical mirrors with respect to the object size. It is the ratio of the height of the image to the height of the object and is denoted as m. The magnification, m produced by a spherical mirror can be expressed as:

m=h_i/h_o

Here, h_i is the height image and h_o is the height of the object.

 Magnification is also equal to the ratio of image distance to the object distance

m=v/u

As the object is always above the principal axis, the height of the object is always positive. But a sign for image height may vary according to the type of image formed. The height of virtual images should be taken positive while the height of real images should be taken negatively.

Uses of Magnification

• A precision magnifier serves the role of a simple magnifier but holds multiple elements to erase aberrations and yield a sharper image.
• A water droplet acts as a simple magnifier which magnifies the object behind it. The water forms spherical droplets due to the influence of surface tension. When the droplet is in contact with an object, a spherical shape is distorted but capable of forming an image.

Activity 

Calculate the magnification if an object of height 3 cm kept in front of a concave mirror gives a real image of size 6 cm

h0 = 3 cm
hi = -6 cm

Magnification , m = hi/ho= -6/3 = -2
                             







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