Question

An object is kept at the centre of curvature of a convex lens of focal length 10 cm. Find the

position and nature of the image​

Answer 1

The position of of the image is -10 cm( behind the mirror) and nature is virtual and erect

Answer 2

Given info : An object is kept at the centre of curvature of a convex lens of focal length 10 cm.

To find : the position and nature of the image are ..

solution : focal length of convex lens , f = 10 cm

so radius of curvature of convex lens, R = 2f = 20 cm

so object distance, u = - 20cm

focal length, f = +10cm

using formula, 1/v - 1/u = 1/f

⇒1/v - 1/-20 = 1/10

⇒1/v = 1/10 - 1/20 = 1/20

⇒v = 20 cm

Therefore position of image is 20cm from the pole of convex lens. (just opposite side of object )

magnification, m = v/u = 20/-20 = -1 , it indicates that image is real and size of image is size of object.