Question

5. An object is 30.0 cm from a spherical mirror,
along the central axis. The absolute value of lateral
magnification is 1/2. The image produced is inverted. who
the focal length of the mirror?
​

Answer 1

Image is inverted ,so it is real.u and v both are nagative, Magnification is  

1

2

 

.

therefore, v=(

u

2

 

)  

Given,u=-30cm,v=-15cm  

Using the mirror formula.

1

v

 

+

1

u

 

=

1

f

 

 

we have

1

f

 

=

1

-15

 

-

1

30

 

=-

1

10

 

 

∴f=-10cm.