Draw ray diagrams showing the image formation by a concave mirror when an object is placed:
Between pole and focus of the mirror.

The diagram given alongside shows a ray of light entering a rectangular block of glass:

1. Copy the diagram and draw the normal at the point of entry.
2. Draw the approximate path of the ray of light through the glass block and out of the other side.

Which type of mirror is used in a solar furnace? Support your answer with reason.

Draw a ray diagram to show the formation of a virtual magnified image of an object by a convex lens. In your diagram, the position of object and image with respect to the principal focus should be shown clearly.

Define:

1. Principal focus of a concave mirror.
2. Focal length of a concave mirror.

A convex lens is immersed in a liquid of refractive index greater than that of glass. How will the nature of lens change?

Write the formula for a lens connecting image distance (υ), object distance (u) and the focal length (f). How does the lens formula differ from the mirror formula?

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.

Which kind of mirrors are used in the headlights of a motorcar and why?

An object of height 4.0cm is placed at a distance of 30cm from the optical centre ‘O’ of a convex lens of focal length 20cm. Draw a ray diagram to find the position and size of the image formed. Mark optical centre ‘O’ and principal focus ‘F’ on the diagram. Also find the approximate ratio of size of the image to the size of the object.