Question

define magnification of a spherical mirror.state new Cartesian sign conventions of mirrors .

Answer 1

Let us consider the height of object is  $h_{0}$.

The height of the image is $h_{i}$

The magnification of a spherical mirror is defined as the ratio of transverse dimension (height) of the image to the transverse dimension of the object. This magnification is also called as the transverse or lateral magnification.

Mathematically magnification can be written as -

                                              $m\ =\ \frac{h_{i}} {h_{0}}$

                                                     

Now we have to define the Cartesian sign conventions for mirrors.

[1] All the measurements are done from the pole of the mirror which is taken as the origin of the coordinate system.

[2] The measurements done along the opposite direction of light is taken as negative.

[3] The measurements done along the direction of light is taken as positive.

[4] All the transverse measurements above the principal axis is taken as positive.

[4] All the transverse measurements below the principal axis is taken as negative.