What kind of lens can form:

1. An inverted magnified image?
2. An erect magnified image?
3. An inverted diminished image?
4. An erect diminished image?

If two lenses (convex) are in contact with each other, what happens to the ray after refraction?

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

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.

A 4 cm tall object is placed on the principal axis of a convex lens. The distance of the object from the optical centre of the lens is 12cm and its sharp image is formed at a distance of 24cm from it on a screen on the other side of the lens. If the object is now moved a little away from the lens, in which way (towards the lens or away from the lens) will he have to move the screen to get a sharp image of the object on it again? How will the magnification of the image be affected?

Briefly describe how you would find the focal length of a concave mirror quickly but approximately.

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.

To find the image distance for varying object distances in case of a convex lens of focal length 15 cm, a student obtains on a screen a sharp image of a bright object by placing it at 20 cm distance from the lens. After that he gradually moves the object away from the lens and each time focuses the image on the screen.

1. In which direction-towards or away from the lens does he move the screen to focus the object?
2. How does the size of image change?
3. Approximately at what distance does he obtain the image of magnification -1?
4. How does the intensity of image change as the object moves farther and farther away from the lens?

List four characteristics of the images formed by plane mirrors.

State and explain the laws of refraction of light with the help of a labelled diagram.