If the image formed by a lens for all positions of the object placed in front of it is always virtual, erect and diminished, state the type of the lens. Draw a ray diagram in support of your answer. If the numerical value of focal length of such a lens is 20 cm, find its power in new cartesian sign conventions.

How would a pencil look like if you saw it through (a) a concave lens, and (b) a convex lens? (Assume the pencil is close to the lens). Is the image real or virtual?

An object 20cm from a spherical mirror gives rise to a virtual image 15cm behind the mirror. Determine the magnification of the image and the type of mirror used.

Mention the types of mirrors used as,

1. Rear view mirrors.
2. Shaving mirrors.

List two reasons to justify your answers in each case.

What is lateral inversion? Explain by giving a suitable example.

An object of size 7.0cm is placed at a distance of 27cm in front of concave mirror of focal length 18cm. At what distance from the mirror should a screen be placed so that a sharply focused image can be obtained? Find the size and the nature of the image.

A ray of light enters a diamond from air. If the refractive index of diamond is 2.42, what % (percentage) is speed of light in diamond with that of speed in air?

An object of height 4.25mm is placed at a distance of 10cm from a convex lens of power +5D. Find:

1. Focal length of the lens, and
2. Size of the image.

Explain why, a stick half immersed in water appears to be bent at the surface. Draw a labelled diagram to illustrate your answer.

A student wants to project the image of a candle flame on a screen 60 cm in front of a mirror by keeping the flame at a distance of 15 cm from its pole.

1. Write the type of mirror he should use.
2. Find the linear magnification of the image produced.
3. What is the distance between the object and its image?
4. Draw a ray diagram to show the image formation in this case.