Draw ray diagrams showing the image formation by a concave lens when an object is placed: At the focus of the lens.

Draw ray diagrams showing the image formation by a convex lens when an object is placed: At infinity.

Refractive index of diamond with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of diamond.

Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case.Object is placed between the focus and device, image formed is enlarged and on the same side as that of the object.

Draw ray diagrams showing the image formation by a convex lens when an object is placed: Between optical centre and focus of the lens.

Draw ray diagrams showing the image formation by a concave lens when an object is placed: Beyond twice the focal length of the lens.

Draw ray diagrams showing the image formation by a concave mirror when an object is placed:At infinity.

Draw ray diagrams showing the image formation by a convex mirror when an object is placed: At finite distance from the mirror.

Draw ray diagrams showing the image formation by a convex lens when an object is placed:At twice the focal length of the lens.

A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like, kerosene or turpentine. Support your answer with reason.