Ray Optics and ...

Consider the following statements:

In a spherical mirror, normal drawn on any point on a spherical mirror passes through :

Why does a straight rod appear bent in water?

Consider the following statements:
(a)  Light bends from its path, when it goes from one medium to another medium
(b)  Speed of light changes, when it goes from one medium to another medium
(c)  Wavelength of light decreases, when it travels from air to water
(d)  Wavelength of light in water $$=\displaystyle\frac{Wavelength   of   light   in   air}{Refractive   index   of   water}$$
Which of the above statements are correct?

Blue colour of sky is due to :

Which of the following (referred to as spherical mirror) depends on whether the rays are paraxial or not?

A spectrum is obtained by sending a beam of white light through a prism. A second prism exactly similar to the first one is placed in an inverted position with the sides parallel to the first. Now

.......... happens when a wave passes from one medium to another at an angle.

A coin kept in a container and not visible can be viewed by pouring water into the container. It happens because of the 

The angle between the normal and refracted ray is called :