Question

an object of height 1 cm is placed in front of a concave mirror of focal length 10 cm such that a virtual image is formed if the height of the image is 3 cm find the object distance

Answer 1

Answer:

Object distance   u=−36 cm

Focal length of concave mirror    f=−12 cm

Using mirror formula :      v1 + u1 = f1

Or    

v1 +  −36 =  −12

1⟹ v=−18 cm

Magnification =   ho/hi =  u/−v

Or      

hi =(−18)

⟹ hi =−18 cm

Image formed is real and inverted