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The Physics PHYA2 thread! 5th June 2013

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Reply 1240
Avatar for NabRoh
NabRoh
11
Original post by StalkeR47
Yes! So, if only 1 criteria is met, only refraction takes place. Am I right?

But that's what we were saying all along! We were saying if both criteria is not met TIR does not take place!!
You were the one saying that as long as one is met TIR can take place
Reply 1241
Avatar for Qari
Qari
20
Original post by StalkeR47
Yes! So, if only 1 criteria is met, only refraction takes place. Am I right?


Exactly so both criteria's have to be met. You just proved what we've been saying
Reply 1242
Avatar for NabRoh
NabRoh
11
Original post by Raimonduo
In simpler terms, for TIR to occur:

(n2<n1)andθi≥θc(n^2<n^1) and \theta^{i}\geq \theta^{c}

Not greater than OR equal to. If it is equal to the crit angle then it will refract along the boundary perpendicular to normal.
Reply 1243
Avatar for NabRoh
NabRoh
11
Original post by Qari
Exactly so both criteria's have to be met. You just proved what we've been saying

I know right!
I think he/she was a little confused tbh.
Original post by NabRoh
To be fair the waves was one was very easy so expect a harder 6 marker.


agreed, formation of a stationary wave is not that difficult to remember once you learn the key parts of it.

Reckon they could ask for an experiment to determine acceleration due to gravity?

Or maybe something on optic fibres discussing the principle features and how they work... idk
Original post by x-Sophie-x
I actually thought so too, but StalkeR47 has a point.
Have you had a looked at Question 6 on June 2009? :smile:


i haveee !!! and it is agreeing with mee. the cladding's refractive index is less than core CHECK !! BUTTTTTT 60degrees is less than 69.3degrees (critical angle) UNCHECK !! therefore you dont get T.I.R. hence it refracts. this means both HAVE to occur for T.I.R
Original post by x-Sophie-x
I get you! yaaaay! :biggrin:

Thank you so much! :smile:


No probs and thanks for understanding my point! :smile: I think it works like this. When You meet 1 criteria(of TIR) and not the other, refraction occurs. When you meet both criteria(of TIR), TIR occurs. when you meet no criteria(of TIR), still refraction occurs. Am I right?:biggrin:
Original post by Qari
Trust us both have to occur


Damnnn :frown:

Wait, I see. I'm trying to look at the question to closely.
Basically that question doesn't confirm anything, because when both conditions are not true it doesn't TIR.

I believe you :tongue: (I think)
Reply 1248
Avatar for Qari
Qari
20
Original post by StalkeR47
No probs and thanks for understanding my point! :smile: I think it works like this. When You meet 1 criteria(of TIR) and not the other, refraction occurs. When you meet both criteria(of TIR), TIR occurs. when you meet no criteria(of TIR), still refraction occurs. Am I right?:biggrin:


Yes, Hallelujah :smile:
Original post by StalkeR47
Yes! So, if only 1 criteria is met, only refraction takes place. Am I right?


exactly broo thats what we have been trying to say !!! and you got sophie to think of it in the wrong way :eek:
Original post by StalkeR47
No probs and thanks for understanding my point! :smile: I think it works like this. When You meet 1 criteria(of TIR) and not the other, refraction occurs. When you meet both criteria(of TIR), TIR occurs. when you meet no criteria(of TIR), still refraction occurs. Am I right?:biggrin:


Yep, see I thought you meant if only one criteria was met then TIR still happens, hence my confusion!
Original post by StalkeR47
No probs and thanks for understanding my point! :smile: I think it works like this. When You meet 1 criteria(of TIR) and not the other, refraction occurs. When you meet both criteria(of TIR), TIR occurs. when you meet no criteria(of TIR), still refraction occurs. Am I right?:biggrin:


had to rep your post there ! got me to calm down knowing you finally understood what we meant phew !! loool
Reply 1252
Avatar for Qari
Qari
20
Original post by x-Sophie-x
Yep, see I thought you meant if only one criteria was met then TIR still happens, hence my confusion!


So do you understand that both have to be met for TIR to occur
Original post by masryboy94
exactly broo thats what we have been trying to say !!! and you got sophie to think of it in the wrong way :eek:

No! All I was saying that why TIR does not occur if incident substance has larger refractive index than the other? Can you answer this? HUH?
Reply 1254
Avatar for Goods
Goods
16
Original post by NabRoh
Not greater than OR equal to. If it is equal to the crit angle then it will refract along the boundary perpendicular to normal.


there is partial diffraction internally at the critical angle that they sometimes want you to draw on as a dotted line. The main ray is along the boundary.

I reckon we might get a single slit diffraction 6 Marker but i can't think of 6 seperate points.
Original post by masryboy94
i haveee !!! and it is agreeing with mee. the cladding's refractive index is less than core CHECK !! BUTTTTTT 60degrees is less than 69.3degrees (critical angle) UNCHECK !! therefore you dont get T.I.R. hence it refracts. this means both HAVE to occur for T.I.R


I KNOW! Omg, why am I so easily persuaded, this is awful D:

Just re looked at it and I see what he was trying to say, but yeah you're right, and I get it :biggrin:
Thanks :h:
Original post by Qari
So do you understand that both have to be met for TIR to occur


No! All I was saying that why TIR does not occur if incident substance has larger refractive index than the other? Can you answer this? HUH? same question. :smile:
Reply 1257
Avatar for Qari
Qari
20
Original post by StalkeR47
No! All I was saying that why TIR does not occur if incident substance has larger refractive index than the other? Can you answer this? HUH?


The incident angle would be lower than the Critical angle
Original post by Qari
The incident angle would be lower than the Critical angle


What about refractive index criteria?
Reply 1259
Avatar for Qari
Qari
20
Original post by Goods
there is partial diffraction internally at the critical angle that they sometimes want you to draw on as a dotted line. The main ray is along the boundary.

I reckon we might get a single slit diffraction 6 Marker but i can't think of 6 seperate points.


At least 1 mark on definition/equation :smile:

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