Some ray diagrams may also show a third ray. Peep holes contain concave lenses. They are set into doors so the occupant can identify a visitor before opening the door.

Usually, four marker questions from the chapter are asked in the CBSE Board Examinations. Derivations, formulas, ray diagrams, and important concepts from ray optics and optical instruments are ...

Once through the lens, the ray should pass through the principal focus. Draw a ray which passes from the object through the centre of the lens. Some ray diagrams may also show a third ray.

12. Suitably match columns A, B, and C. 13. Observe the ray diagram and answer the questions. (a) State the optical phenomenon shown in this diagram. (b) Will this phenomenon take place if the ray ...

Focusing on easy but scoring topics, clean presentation with well-labelled diagrams ... based questions which have been added ...