Ray Optics and ...

Why are red coloured lights are used in traffic signals to stop the vehicles?

The colour which has least critical angle is

A bird is flying $$12 m$$ above the surface of a pond. What is the apparent position of the bird as viewed by a fish $$1m$$ below the surface? ($$_{a}\mu _{w}=\cfrac{4}{3}$$)

The bending of light as it passes from one medium into another is commonly known as

ABCD represents a glass slab and PQRS indicates the path of a light ray passing through the slab.If the refractive index of the glass is $$\sqrt{3}$$, find 'x'.

A bird flying above a pond starts moving vertically down towards the water below at a speed of $$v \ m  s^{-1}$$. Find its apparent velocity as viewed by a fish located at a depth of $$d$$ m below the surface of water of refractive index $$\mu $$.

When light travels from one medium into another it suffers

The figure shows cross section of a hollow glass tube of internal radius $$r$$, external radius $$R$$ and index of refraction $$n$$. For two rays DE and ABC (in which DE lies on ODE and DE is parallel to BC), the separation $$r_1$$ will be :

A beam of light consisting of red, green and blue is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47 respectively. The prism will

A thin lens with focal length f to be used as magnifying glass. Which of the following statements regarding the situation is true?