Page 2 - Lesson-sign convention rules of spherical mirror
P. 2
Mirror formula and magnification
Mirror formula:-
It gives the relationship between image distance (v) , object distance (u) and the
focal length (f) of the mirror and is written as
1v+1u=1f1v+1u=1f
Where v is the distance of image from the mirror, u is the distance of object from the
mirror and f is the focal length of the mirror. This formula is valid in all situations for
all spherical mirrors for all positions of the object.
Magnification
Magnification produced by a spherical mirror gives the relative extent to which the
image of an object is magnified with respect to the object size. It is expressed as the
ratio of the height of the image to the height of the object. It is usually represented by
the letter m. So,
The magnification m is also related to the object distance (u) and image
distance (v) and is given as
m=h1/h2=−v/u
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