Question

: An object of height 10 cm is placed 15 cm away from concave mirror of
focal length 12 cm find position, Nature and size of the image form.​

Answer 1

Object distance   u=−36 cm

Focal length of concave mirror    f=−12 cm

Using mirror formula :      

v

1

​  

+  

u

1

​  

=  

f

1

​  

 

Or    

v

1

​  

+  

−36

1

​  

=  

−12

1

​  

 

⟹ v=−18 cm

Magnification    

h  

o

​  

 

h  

i

​  

 

​  

=  

u

−v

​  

 

Or      

10

h  

i

​  

 

​  

=  

−10

−(−18)

​  

 

⟹ h  

i

​  

=−18 cm

Image formed is real and inverted.