An object 2 cm in size is placed 30 cm in front of a concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? What will be the nature and the size of the image formed? Draw a ray diagram to show the formation of the image in this case.

Here,   h = + 2 cm,   u = - 30 cm,   f = -15 cm
As               
        
or                                  
Thus, the screen should placed at 30 cm in front of the mirror so as to obtain the real image.
Magnification,  
Image size,  h' = 
The image is real, inverted and of the same size as the object. The image formation is shown in the ray diagram given below.