When a ray of light is Travelling from a denser to a rarer medium and the angle of incidence is equal to the critical angle then the angle of refraction in the rarer medium is?

Transcript

questions for array of light travelling from a denser medium of refractive index and 12 rarer medium of refractive index and to that end to buy an equal to sin I see where I see is the critical angle of incidence for the media in second part is explain with the help of a diagram how the above principle is used for the transmission of media video signal using Optical Fibre we have to prove that this end to buy an equal to time they let se this is a boundary with the separating two medium one is rare and another one is denser than the refractive index of the dancer 1 and 1 it is given and refractive index of the Year 1 and 2 and 2 it is given that ok

now let's say this is a normal this is a normal but suppose I'm media with extended like this and have different conditions where different cases in first case let se sources hear it incident light from this so incident on this surface at an angle of incidence I and it this and it will bend it because it is moving from the denser to rarer medium and we know that that when the Le when the Re travels from the denser medium to the rear medium it will bend away from the normal ok this gave the angle of refraction at this hour let's suppose from this source another array strikes at this

at this and this somewhere like this that means on increasing the angle of incidence if this is I want this is why do we can clearly see that it is better than anyone that means if you're an increase in the angle of incidence we can observe that this is Almond this is our to then this R1 is R2 R1 and R2 more close to the 90 degree ok let's suppose let's suppose a Re is our is coming from this and its rights at an angle of IC let se at certain angle I see such that the Re after spending it refract at an angle of 90 degree at an angle of 90 degree

angle of incidence at with that angle of incidence at with the angle of refraction is 90 degree that angle is known as angle of the triangle is known as Critical Angle that angle is known as Critical Angle for this I see is known as critical and ok angle of incidence Batman this angle at which the angle of refraction become 90 degree ok let's say this is point P at point point at point P apply snell's law apply nails law which says new 1991 equal to new to sign hai to show the rays coming from this denser medium that is refractive index N1 so this N1

angle of incidence is icicib22 end-to-end to angle of refraction is 90 degree in such case so sin 90 and 91 1991 that means this sign I see this is will be equal to N to buy Anmol I see this week we'll to into by animal ok this is because if what if we increase what if we increase the angle of incidence greater than just let se strikes at the surface and this I is better than this I see that is the angle of incidence the fact that it is better than the critical angle of incidence will not go into the rear medium it will reflect back into the same medium that is a denser medium

ok so if that condition appears that the angle of incidence becomes greater than the critical angle of incidence in such case there will be a tree that is the total internal reflection that it is I is greater than I see then the then the Re does not detract or travel into the another medium tap it reflects back into the same medium it reflects back into the same medium into the same medium this is known as this is known as PR that is total internal reflection is known as total internal reflection principal has many application and one of the important application of this phenomenon is the optical fibre

Optical Fibre Optical Fibre is basically a transmitting signal wire it is a medium basically it is a transmitting medium that is a transmitting or transmitting medium which is used to carry the optical signal without any appreciable loss without any appreciable loss how let se this is the core this is the core of this optical fibre and this Poll is surrounded and this is surrounded by another medium another medium which is known as cladding this is known as cladding ok this cladding has a refractive index to

underscore has a Refractive Index new one ok and this new one is better than this new tool that means the inductor is better than the refractive index of the cladding what will happen if let se are incident on this this is the normal this is an array is incident on this at an angle of incidence I attend angle of incidence so it will then it will bend towards the normal will bend towards the normal like this version of it was like this surface it was like the surface that is the interface between this Core and cladding such that this angle of incidence water be the angle of incidence this net se ideas

this I dash will be greater than the IC Zydus will be better than this I see which is the critical angle for this and this time I see this time I see this will be equal to this will be equal to new to buy an equal to YouTube by Google OK angle of incidence is such that it is greater than the critical angle of incidence angle of incidence is better than this critical angle of incidence this will show the the Rebel show the TR that the Re does not travel to the cladding it will reflect back into the core course that means the signal will face total internal reflection and there will be minimum loss let is no appreciable of admittance a minimum

minimum loss in this case so this is how this Optical Fibre uses the concept of this total internal reflection to transfer data signal from one place to another ok thank you