Questions

HCHO: The carbon and and the oxygen are bonded through a double bond which counts as "one electron pair". Hence the molecule has three electron pairs and is trigonal planar.

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.

The Farmers Alliance was an organized agrarian economic movement among American farmers that developed and flourished in 1875.

One of the goals of the organization was to end the adverse effects of the crop-lien system on farmers in the period following the American Civil War.

The Farmer's Alliance moved into politics in the early 1890s under the banner of the People's Party, commonly known as the "Populists."