An object placed on a metre scale at 8 cm mark was focussed on a white screen placed at 92 cm mark, using a converging lens placed on the scale at 50 cm mark.

1. Find the focal length of the converging lens.
2. Find the position of the image formed if the object is shifted towards the lens at a position of 29.0 cm.
3. State the nature of the image formed if the object is further shifted towards the lens.

If an object of 10cm height is placed at a distance of 36cm from a concave mirror of focal length 12cm, find the position, nature and height of the image.

A convex lens of focal length 25cm and a concave lens of focal length 10cm are placed in close contact with one another.

1. What is the power of this combination?
2. What is the focal length of this combination?
3. Is this combination converging or diverging?

A man sits in an optician's chair looking into plane mirror which is 2m away from him and views the image of a chart which faces the mirror and is 50cm behind his head. How far away from his eyes does the chart appear to be?

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.

State and explain the New Cartesian Sign Convention for spherical lenses.

Describe the New Cartesian Sign Convention used in optics. Draw a labelled diagram to illustrate this sign convention.

Describe with the help of a ray diagram the nature, size and position of the image formed when an object is placed in front of a convex lens between focus and optical centre. State three characteristics of the image formed.

The two rays chosen for the construction of ray diagram is:

Ray 1: When the incident ray is parallel to the principal axis, the reflected ray will pass through the focus of concave mirror or it appears to pass through the focus of convex mirror.
Ray 2: When the incident ray passes through or appears to pass through the centre of curvature, the light, after reflection from the spherical mirror, reflects back along the same path.
The image formed is real, inverted, magnified and is formed beyond the centre of curvature.

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.