An object of 5.0cm size is placed at a distance of 20.0cm from a converging mirror of focal length 15.0cm. At what distance from the mirror should a screen be placed to get the sharp image? Also calculate the size of the image.

Distinguish between a real and a virtual image of an object. What type of image is formed?

1. By a plane mirror.
2. On a cinema screen?

Draw ray-diagrams to show the formation of images when the object is placed in front of a concave mirror (converging mirror):

1. Between its pole and focus.
2. Between its centre of curvature and focus Describe the nature, size and position of the image formed in each case.

With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.

If the image formed by mirror for all positions of the object placed in front of it is always virtual and diminished, state the type of the mirror. Draw a ray diagram in support of your answer. Where are such mirrors commonly used and why?

An object is placed at a distance of 100cm from each of the above lenses A and Calculate:

1. Image distance, and
2. Magnification, in each of the two cases.

Draw a diagram to show how a converging lens held close to the eye acts as a magnifying glass. Why is it usual to choose a lens of short focal length for this purpose rather than one of long focal length?

How far should an object be placed from a convex lens of focal length 20cm to obtain its image at a distance of 30cm from the lens? What will be the height of the image, if the objects is 6cm tall?

State where an object must be placed so that the image formed by a concave mirror is:

1. Erect and virtual.
2. At infinity.
3. The same size as the object.

An object of height 4cm is placed at a distance of 15cm in front of a concave lens of power, -10 dioptres. Find the size of the image.