If a ray of light enters from alcohol to air. The refractive index of alcohol is 1.36. Calculate the speed of light in alcohol with respect to air.

The focal length of a lens is +150mm. What kind of lens is it and what is its power?

List four properties of the image formed by a plane mirror.

What are the important differences between looking at a photograph of your face and looking at yourself in a plane mirror?

The linear magnification produced by a spherical mirror is +3. Analyse this value and state the (i) type of mirror and (ii) position of the object with respect to the pole of the mirror. Draw ray diagram to show the formation of image in this case.

With the help of a ray diagram explain why a concave lens diverges the rays of a parallel beam of light.

An extended object in the form of an arrow pointing upward has been placed in front of plane mirror. Draw a labelled ray-diagram to show the formation of its image.

Draw diagram to represent the action of a concave mirror on a beam of parallel light rays. Mark on this diagram principal axis, focus F, centre of curvature C, pole P and focal length ƒ, of the concave mirror.

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