Fermat's Principle to Snell's Law (Derivation)

Light has a peculiar property. When a light ray goes from one point to another, it travels via the path that takes the least amount of time. This is known as Fermat's Principle. Or, Principle of Least time.

The Fermat's Principle can be used to explain why light bends as it goes from one medium to another. It can be used to prove the Snell's Law which gives the relationship between angle of incidence and angle of refraction.

In this video I discuss these above things.

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PLAYLIST on Various Problems on MECHANICS

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[randomkeyboardsmash]

Finally video with chalks and boards

Is it only me or others also feel these videos are better than the one where he shows his computer screen?

[mahendramosalpuri]

Your way of delivering content extremely effective and easily understandable thank you so much sir you are awesome

[bilalphysics]

Your explanation is quite unique...
Please choose a series

[chandanaprasad]

The most underrated channel on physics... stunning explanation

[AnirbanMajumdar-tisu]

First of all, how you have taught nuclear and particle physics is just outstanding!! These lectures are very good to learn and understand physics.

I have a demand that please make a series on details about Standard Model and Beyond Standard Model Phenomenology (Including Neutrino physics, dark matter physics, collider physics, lattice gauge theory etc) using QFT treatment. It will be really helpful to learn Standard Model from you

[toastedsniper]

Perfectly done and explained, I love your enthusiasm sir.

[chanakyaprasad]

Your style of Chalk and talk is the

Please Please Do share your knowledge on competitive exams like CSIR NET.

[chinnagunttilakshmikanth]

Really ur rockstar of physics what an explanation sir... Really awesome

[ebutuoy]

Love it!, you are the best physics teacher I have met

[davidgiambra]

On the right side of your equation, you wrote I think that you meant to write

[HimmatBording]

Sir keep us taught using this green Board. It looks so good like classroom.
That digital marker and digital board doesn't feel like that.

[ankitnautiyal]

Great video. Appreciate the great service you are doing to make physics very very nicely.
This video does explain how Fermats Principle implies Snell's law. Why light behaves like this is probably explained better through Huygen's wave theory.
Requesting for a follow up video ☺️.

Perhaps now at quantum level there might be some other theory which I have no idea about and it would be great if it can be covered.

[doutormanhattan]

Great video.
But there is a little mistake in the denominator (hypotenuse) in the right term. You used x² instead of y2².

[AbhishekAbhishek-txem]

Thanks a lot sir. But in 9:21 we have considered theta 1 as n1, and theta 2 as n1. So it shouldn't be n2/n1 right...?

[PhysicsFunwithDharmeshKareliya]

I was exploring answer of the question why light is in hurry. And it's still a question. By the way your video are always good.

[physicsvideos]

Sir I saw your nuclear physics videos . Can you suggest a book ? Please

[anandmohan]

Sir, Pl clear these doubts
[A (1) How you fixed Points A & B. ( 2) In the differentiation how you treated 'x' is variable and 'y' is Constant.
[ B ] Pl. correct the second part where t= { 1st part } + { second part }*
{C } it is a direct Result from REFRACTION EXPT of Glass SLAB.
Why this much beating about the BUSH ???

[vishalmishra]

but how this derivation proves that light can take path which is not straight line

[AmanDeepSingh-dduq]

This also proves faster than light is possible and mass associated with that mass should be phase mass as quanta which depends opon probability.

[sciencefatcz]

Sir, I want to talk to u.
Any method?
Please let me know sir🥺