Suppose you have three concave mirrors A, B and C of focal lengths of 10 cm, 15 cm and 20 cm. For each concave mirror you perform the experiment of image formation for three values of object distance of 10 cm, 20cm and 30 cm. Giving reason answer the following. (i) For the three obuject distances, identify the mirror mirrors which wil form form an image of magnification -1. (ii) Out of the three mirrors identify the mirror which would be preferred to be used for shaving puposes/ makeup. (iii) For the mirror B draw ray diagram for image formation for object distances 10 cm and 20 cm.

Suppose you have three concave mirrors A, B and C of focal lengths of

1.	Suppose you have three concave mirrors A, B and C of focal lengths of 10 cm, 15 cm and 20 cm. For each concave mirror you perform the experiment of image formation for three values of object distance of 10 cm, 20cm and 30 cm. Giving reason answer the following. (i) For the three obuject distances, identify the mirror mirrors which wil form form an image of magnification -1. (ii) Out of the three mirrors identify the mirror which would be preferred to be used for shaving puposes/ makeup. (iii) For the mirror B draw ray diagram for image formation for object distances 10 cm and 20 cm.
Answer» Solution :`f_(a)=10cm f_(b)=10cm, f_(c)=20cm` `u_(1)=10cm, u_(2)=20cm, u_(3)=30cm` (i) `m=-1` MEANS `u=2f, ` for `Atou_(2)`, for `Btou_(3)` (ii) Mirror B or C- distance should be less than FOCAL erect and magnified image, face is generally kept at a distance more than 10 cm.