Скачать или смотреть Why should we take parallel rays from infinite distance object?

#whyahouldwetakeparallelraysfrominfintedistanceobject? #reflection #refraction #activity
To verify this we must first find out some way of obtaining a beam of parallel rays. How do we do that?
First we need to create a situation in which one gets #parallelrays of #light.
In the figure we have stuck two pins on a thermocole block. The pins are parallel to each other. As we see in the figure, when a source of light is kept very near, we see the shadows diverging
(From the base of the pins). As we move the #source away from the pins, the angle of divergence gets reduced. If we move the source far away we will get parallel shadows. But as we move the candle away, the light intensity becomes low. That means to get a beam of parallel rays the source should be at a long distance and it must be of sufficient intensity.
Where do we find one such source?
Yes, we have one easily available source, you probably have guessed it: The Sun.
Let us do an experiment with sun rays and a concave mirror, after reflection the light rays converges at focus.so incident light rays are parallel to each other.


CONCLUSIONS
1.The beam of light witch is coming from infinite distance, all the rays will be parallel to each other.
2.Parallel beam of rays after travelling infinite distance they will converge.