“A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw labeled ray diagram to justify this statement.

A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?

Explain how to read the following message which was found on some blotting paper:

Explain what is meant by a virtual, magnified image.

The lens A produces a magnification of, -0.6 whereas lens B produces a magnification of +0.6:

1. What is the nature of lens A?
2. What is the nature of lens B?

The optician’s prescription for a spectacle lens is marked +0.5D. What is the:

1. Nature of spectacle lens?
2. Focal length of spectacle lens?

List two possible ways in which a concave mirror can produce a magnified image of an object placed in front of it. State the difference, if any, between these two images.

What is the difference between a real image and a virtual image? Give one example of each type of image.

A student focuses the image of a well illuminated distant object on a screen using a convex lens. After that he gradually moves the object towards the lens and each time focuses its image on the screen by adjusting the lens.

1. In which direction-towards the screen or away from the screen, does he move the lens?
2. What happens to the size of the image-does it decrease or increase?
3. What happens to the image on the screen when he moves the object very close to the lens?

An object is placed at the following distance from a convex lens of focal length 15cm:

1. 35cm
2. 30cm
3. 20cm
4. 10cm

Which position of the object will produce:

1. A magnified real image?
2. A magnified virtual image?
3. A diminished real image?
4. An image of same size as the object?