Question

1. light takes the shortest path to travel
2. when it enters an optically denser medium, it bends towards the normal, so as to travel faster

My question is, when light enters an optically rarer medium from an optically denser medium, it bends away from the normal, even if bending towards the normal could have helped it to travel faster. why does this happen so?

Answer 1

ANSWER.

✦*REFRACTION*.
it is the phenomenon of change in the path of light , when it moves from one medium to another.



✦THERE IS TWO TYPE OF MOTION POSSIBLE.

(1) NORMALLY

(2) MAKING SOME ANGLE


*✦NORMALLY *.

When light ray fall normally on a surface then it will goes straight no any bending will take place .



✦*BENDING *.

When light ray make some angle with the surface then it bend . because of change in velocity because light ray have different velocity in different mediums .




✦NOW HERE WE DISCUSS ON BENDING IN DETAILS.




(1) REASON OF BENDING.

As we know light have different velocity in different medium .
and when light moves from rarer to denser and denser to rarer then it becomes bend because it wants to maintain it velocity.


✦CASE 1st(RARER TO DENSER)
when light moves from rarer to denser then it becomes bend towards normal .


✦REASONS.

Light ray bend towards normal because it's want to maintain it speed . I tell u clearly as u know in rarer velocity of light is more ( particles are far away) and in denser velocity of light will be slow due ( particles are closer ) . now light travelled from rarer to denser mean first it velocity higher now when it strike to the surface then it enter into denser medium here it's velocity decrease so for maintaining it initial velocity it bend away


✦STUDY DEEPLY


as we know

$wavelength = \frac{velocity}{frequency}$

mean for maintaining their velocity it should be need higher wavelength .so it bend towards normal


according to* Snell's law *

if refractive index is more ( Medium is denser)

then angle alpha is less. so it bend towards normal.



✦NOW YOUR QUESTION.

According to you, the light should be bands on the side of the normal so that it moves faster. then why when light travelled from denser to rarer it moves away from normal.


yes, it is right that light ray want to be a list time in it's motion.


but friend when light moves in different mediums and it velocity change and it try to maintaining it velocity. so in case of denser to rarer . first, light have lower velocity as compared to second medium so it's want to maintaining it speed so,it increase it path by bending away from normal.





✦BY Snell law .
according to Snell's law the angle alpha is greater in rarer Medium ( which have higher refractive index)


so make a large angle it bend away from normal

Answer 2

Answer:

Answer:When light ray make some angle with the surface then it bend . because of change in velocity because light ray have different velocity in different mediums .