Biology; Chemistry; Physics: Post your doubts here!

[a.abid]

Yes, it is wrong in past paper it is. Sin63/sin40 .... But shouldn't 40 be the angle of incidence...

No, it can't be cuz we only take it as the angle of incidence wen light ray is entering the block,since it has already entered, 63 forms the angle of emergence. But if u think its difficult-just take it the easy way-sin ofbigger angle/sin of smaller angle.

 

[Talhakhan]

U can also use another method to solve this question:
refractive index= 1/sin critical angle
Since critical angle is 46,so ref. index will be 1/46=1.39 which is the same as sin63/sin40

I know that formula to but why are we using incident angle as 63 ..we always take the incident angle to be 40 as arrows indicate...

 

[a.abid]

I know that formula to but why are we using incident angle as 63 ..we always take the incident angle to be 40 as arrows indicate...

We only take it as angle of incidence wen light ray is ENTERING the block.Since it has already ENTERED we cant appply the same formula.We have to apply the other formula:
Sin of angle of emergence(63)/sin of angle of refraction(40)
Hope u got it

 

[asd]

Tell me the types of lenses used in projector and in photographic enlarger

 

[Fallen316]

Tell me the types of lenses used in projector and in photographic enlarger

convex.

 

[asd]

convex.

And the nature of the image formed? as in real, inverted/virtual, magnified?

 

[Translucent231]

in the formula sin(i)/sin(r) the i must always be the angle of the ray with the normal in AIR or VACUUM, nothing else.

 

[Fallen316]

And the nature of the image formed? as in real, inverted/virtual, magnified?

real, inverted, magnified

 

[Talhakhan]

And the nature of the image formed? as in real, inverted/virtual, magnified?

Inverted , real and magnified...

 

[ashiqbal]

The final hours of preparation:

-just go once through the past papers very very briefly, doing as many as you can! just stop on three or four marks question which are a bit difficult, and understand the concept, then move forward!
-take a light dinner
-pray to Allah before going to bed that you are able to apply the concepts that you have studied in tomorrow's paper!
-goto bed early(i mean before 12:00 am)
-in the morning, wake up early, and after praying, glance the most difficult topics of book once!

This is what i do before exams, it sure helps my nerves and my preparation!

Good luck to you all! May you attempt the examination with chances of A* high with the grace of Allah!

 

[Talhakhan]

The final hours of preparation:

-in the morning, wake up early, and after praying, glance the most difficult topics of book

which are the most difficult topics in the book ... Just tell so that i can revise/prepare them....

 

[a.abid]

Best Of Luck Everyone
Hope we all do good and get A*s InshAllah
And that the paper is easy...lol
(Ameen)

 

[syed1995]

I am soo screwed :\

 

[Talhakhan]

Best Of Luck Everyone
Hope we all do good and get A*s
And that the paper is easy...lol
(Ameen)

INSHALLAH!!!

 

[syed1995]

Best Of Luck Everyone
Hope we all do good and get A*s InshAllah
And that the paper is easy...lol
(Ameen)

Ameen .. wesay paper hard aanay wala hai .. sunnay mein aaya hai..

 

[Talhakhan]

I am soo screwed :\

Why??

 

[a.abid]

Ameen .. wesay paper hard aanay wala hai .. sunnay mein aaya hai..

DONT tell me I havent even prepared sahi trhan say

 

[Talhakhan]

Ameen .. wesay paper hard aanay wala hai .. sunnay mein aaya hai..

Inshallah jo hamaray liya acha hai wo hi ALLAH karai ho....

 

[a.abid]

Inshallah jo hamaray liya acha hai wo hi allah karai ho....

*Allah

 

[syed1995]

Why??

Tayyari bilkul bhi nai hai ( And i am really weak in theory .. MCQ mein tu aajayeingay Insha Allah 38-39/40 Theory ka Masla hai