Question

the object distance of a lens is-30 cm and image distance is -10cm find the magnification of the lens with the help of this decide wheather the size of the image is smaller or bigger than the size of the object

Answer 1

magnification of a lens = v/u
m = -10/-30
= 10/30
= 1/3
= 0.333...
is the magnification and the image formed is smaller than the size of the object

Answer 2

Formula for finding the magnification of lens:

Magnification= Size of image/ size of object= Image distance/ Object distance

Here, Image distance= -10cm

Object distance= -30cm

Therefore, Magnification= -10/-30= 0.33

According to the formula, if the magnification is less than 1, then it means that the size of the image formed is smaller than the size of the object and vice-versa.

Here, magnification comes to 0.33 so it indicates that the image size is smaller than that of the object.