Question

An object 6 cm in size is placed 30 cm in front of a convex 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.

Answer 1

•Given:-

➠Height of the object (h)=6cm

➠Distance of the object (u)=-30cm

➠Focal length of the object (f)= +15cm. [As there is convex mirror so the focal length is positive]

•To find out

➠Distance of the image formed (v)=?

➠Nature and the size of image formed in front of convex mirror=?

•Calculation:-

Using mirror formula we have

1/f=1/v+1/u

⇒1/v=1/f-1/u

⇒1/v=1/15+1/30

⇒1/v=2+1/30

⇒1/v=3/30

⇒v=30/3

⇒v=+10 m

Here we can see that v=+10 m is positive.Therefore the nature image will be virtual and erect and its size will be diminished.

Ray diagram has been showed above and the image formation also took in same ways as shown in figure.