Questions

Numismatist: someone who studies or collects coins, paper money, or medals.

Philatelist: a person who collects stamps.

Ornithologist: a person who studies on birds.

Statistician: an expert in the preparation and analysis of statistics.

A Mirage is a naturally occurring optical phenomenon in which light rays bend to produce a displaced image of distant objects or the sky.

• It is caused due to Total internal Reflection.

• It is an optical illusion observed in deserts or hot summer days due to which a person sees a pond of water some distance ahead of him in which the surrounding objects appear inverted.

How Mirage Forms::

1. The temperature of other layers of atmosphere goes on decreasing as we go up.
2. Therefore density and refractive index of air changes as one goes up.
3. Thus a ray of light,gets refracted more and more away from the normal.
4. At a particular angle when a ray of light exceeds critical angle, total internal reflection takes place and ray of light gets reflected in the same medium.
5. when the reflected ray reaches our eye, it appears as coming from tree or sky .
6. Hence the inverted image of tree creates an impression from a pond of water.

Mixed heart means the heart in which the oxygenated and the deoxygenated blood is mixed. Reptiles and amphibians have mixed heart.

Tea bag is what it will go in dry and come out wet, the longer it is in, the stronger the tea we will get.