Question

It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm. (i) What should be the range of distance of an object placed in front of the mirror? (ii) Will the image be smaller or larger than the object. Draw ray diagram to Show the formation of image in this case. (iii) Where will the image of this object be, if it is placed 24 cm in front of the mirror ? Draw ray diagram for this situation also to justify your answer. Show the positions of pole, principal focus and the center of curvature in the above ray diagrams.

Answer 1

Given concave mirror of focal length =f= 12cm

i)

To get an erect image the object must be placed between Pole and Focus :

object must be placed  less than 12cm

II) Nature of image formed :

Image is formed behind mirror

• Virtual
• Erect
• Enlarged

Refer the attachment for ray diagram

iii) When object is placed 24cm from the mirror then image will be formed C

Because object is on C

• Nature of image
• Same size
• real
• inverted