What is spectrum? What is the name of glass shape used to produce a spectrum?

A beam of light consisting of consists of three. namely red (R), Green (G) and yellow (Y) on the prism as shown below. Complete the diagram to show refracted and emergent ray.

What happens to the image distance in the eye when we increase the distance of an object from the eye?

What happens when a beam of sunlight enters a dusty room through a window? Explain your answer.

Why are the ‘danger signal’ lights red in colour?

A star sometimes appears brighter and some other times fainter. What is this effect called? State the reason for this effect.

When a light ray passes obliquely through the atmosphere in an upward direction how does its path generally change?

An object is moved closer to an eye. What changes must take place in the eye in order to keep the image in sharp focus?

Which colour of light has.

1. Minimum speed in glass?
2. Minimum frequency?

How does the eye adjust itself to deal with light of varying intensity?