The focal length of converging lens is 20 cm , Where will the image be formed, if an object is placed at 60 cm from the lens? Write characteristics of the image.

From the thin lens formula, 1 f = 1 v + 1 u where, f is the focal length v is the distance of the image from the optical center u is the distance of the object from the optical center Given, f = + 20 cm u = - 60 cm Substituting all the values in the lens formula, we get 1 20 = 1 v - 1 ( - 60 ) ⇒ 1 v = 1 20 - 1 60 ⇒ v = 20 × 60 60 - 20 = + 30 cm So the image will be formed at 30 cm from optical center on other side of lens. The image will be real, inverted and smaller.

Can a virtual image be photographed by a camera?

A real image occurs when rays converge, but the virtual image occurs when rays appear to diverge. Yes, we can take a photograph of a virtual image by a camera. The best example is taking a photo of ourselves or our image formed in the plane mirror, which is a virtual image. A virtual image is formed when the diverging rays are tracked backwards and made to intersect at some point. The rays coming from a virtual image gets refracted by the camera lens, and form a real image. Our eyes also work in the similar way. When we stand in front of a mirror, the virtual image is projected to our eyes as a real image in the retina.