Question

When the height of image is less than the height of object, then magnification will be:
A) Less than 1
B) Greater than 1
C) Equal to 1
D) Zero

Answer 1

Hint: the magnification of lens or mirror is given by the ratio of height of image to the height of object. So, if the numerator is smaller than the denominator then the fraction is less than 1. Also if the image is smaller than the object, magnification is less than 1 because the image generated is smaller than the actual object.

Complete step by step solution:
When the height of image is less than the height of object, then magnification will be less than 1 because formula for magnification is given as:
$m = {{{h_i}} \over {{h_o}}}$ where, ${{h_i}}$=height of image and ${{h_o}}$ = height of object.
The magnification is defined as the ratio of height of image to the height of object. Also the ratio of image distance to object distance.

The magnification defines the type of image formed according to the position of object and image or height of object and image. For an image to be a real image, its magnification should be between 0 to 1. If the height of the image is more than that of the object then the image is considered as virtual. The magnification of a lens also depends upon the focal length of the lens. With help of magnification we can define the application for the lens. For example for magnifying glass, a lens having magnification greater than 1 is required. The magnification also depends on the distance of the object.

Note: if the magnification is less than 1 then the height of image formed is less than that of object and if magnification is greater than 1, then height of image is more than that of object. For a lens to have a clear magnification, it should have a definite focus and accurate measurements.