If the object is moved further away from the mirror, what changes are there in the position and size of the image?

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.

Which lens would you prefer to use while reading small letters from a dictionary?

List two properties of the images formed by convex mirrors. Draw ray diagram in support of your answer.

“A concave mirror of focal length ‘f’ can form a magnified erect as well as an inverted image of an object placed in front of it.” Justify this statement stating the position of the object with respect to the mirror in each case for obtaining these images.

The refractive indices of glass and water with respect to air are 3/2 and 4/3 respectively. If speed of light in glass is 2×108 m/s, find the speed of light in water.

A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.

A lens has power 4D. Find the focal length that lens.

Draw a labelled ray diagram to show the formation of image of an object by a convex mirror. Mark clearly the pole, focus and centre of curvature on the diagram.

List four characteristics of the images formed by plane mirrors.