GRE Questions

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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 statement mentions that he will pass if he is intelligent.So,1 is implicit.further,this means that it is not necessary that he will pass.So, 2 is not implicit

So he is facing west his left hand will be in North direction.

The given letter equation 6 B in an O refers to 6 Balls in an Over.

Clearly A whishes to study the degree of effect of pay revision on job satisfaction of employees.This means that job satisfaction can be measured and A is capable of making such a study.So,both are not implicit

Tether is a rope, chain, or the like, by which an animal is fastened to a fixed object so as to limit its range of movement.

Cord is rope like to tie. Hence, cord is most similar in meaning to tether.