Revision Progress

[fungkhmax]

Hey guys, just like many of you here, I will be taking the summer 2017 IGCSE exams session soon. I think that it would be a good idea to tell each other about our progress for revision for IGCSE

Ill start off
Bio: 10 units left to go through in notes + haven't start past paper
Chem: Almost fully prepared, need more time for past papers and syllabus
Math: 90% prepared, need to be more consistent with getting A's on paper 2 and 4
Chinese: 80% prepared
English: 80% prepared
Econ: Need more time with past papers, consistency issues with achieving A*

Good luck with your revision!

 

[Ayesha Asif333]

Bio: 10 units left to go through in notes + haven't start past paper

whaaaa ....how are you gonna manage, just two weeks left and believe me they're making difficult papers

Chem: Almost fully prepared, need more time for past papers and syllabus
Math: 90% prepared, need to be more consistent with getting A's on paper 2 and 4

Yea, same here

English: 80% prepared

Well, i've done absolutely nothing for this subj

Good luck with your revision!

All the best to you too!

 

[fungkhmax]

whaaaa ....how are you gonna manage, just two weeks left and believe me they're making difficult papers

Haha I only have 2 units left to go through, progress is quick since we did our mocks earlier this year, just need a quick refresh

 

[Ayesha Asif333]

Wow, now this is what I call…true confidence and satisfaction

Look at me – have done pp from 1994 to 2016 for physics but still think my physics preparation is burning in hell:X

 

[fungkhmax]

Wow, now this is what I call…true confidence and satisfaction

Look at me – have done pp from 1994 to 2016 for physics but still think my physics preparation is burning in hell:X

Haha I started preparing wayyy to late for my IGCSE's, I have confidence since I scored 87% (A*) overall for my biology in mocks.
(P.S. I have 2 subjects that i havent studied for yet, ICT theory and DT)

 

[Ayesha Asif333]

Haha I started preparing wayyy to late for my IGCSE's, I have confidence since I scored 87% (A*) overall for my biology in mocks.
(P.S. I have 2 subjects that i havent studied for yet, ICT theory and DT)

You could have, in other words simply said that you are a super smart an exceptionally intelligent person *_* ( and there's nothing wrong in appreciating one's own self )

Seldom do i come across such people

 

[fatimaw]

U GUYS ARE SCARING ME

 

[Ayesha Asif333]

U GUYS ARE SCARING ME

Im sorry....
When and what's ure next paper

 

[fatimaw]

biology this Tuesday and tryin my best to get A* in this

 

[fatimaw]

ook at me – have done pp from 1994 to 2016 for physics but still think my physics preparation is burning in hell:X

wow i just cant believe tht how do u manage your time soo effectively

 

[fungkhmax]

Haha calm down, get more rest. Actually im the one who is supposed to be scared imo, havent started revising for ICT. Kinda dug myself a grave...

 

[Ayesha Asif333]

biology this Tuesday and tryin my best to get A* in this

Oh ok ...all the best ...I too have it tomorrow

 

[Ayesha Asif333]

wow i just cant believe tht how do u manage your time soo effectively

U worry and wonder not....my teacher made us do them ....besides it's the quality that matters and not the quantity

 

[Ayesha Asif333]

Haha calm down, get more rest. Actually im the one who is supposed to be scared imo, havent started revising for ICT. Kinda dug myself a grave...

True that

 

[fatimaw]

can someone help me with this question i would be grateful and also explain i dont get this proportionality stuff

 

[whyareallnamestaken]

can someone help me with this question i would be grateful and also explain i dont get this proportionality stuff
View attachment 62110

Resistivity of any given material depends upon three factors:

1. Length (direct proportion: more length = more resistance)

2. Material (Conductors such as copper have less resistivity)

3. Cross sectional area (inverse proportion: more cross sectional area = less resistance)


Now, before I answer the question you've sent, it is important for you to know that if an object's diameter is twice that of the other, then their cross sectional areas will be present in the ratio 4:1.


This so happens because the area of a circle is πr^2


When you double the diameter, the radius doubles as well.


So if an object A were to have a radius of R and the radius of object B was twice that of R, then their cross sectional areas would be worked out this way:


CA of A:


π(R)^2


CA of B:


π(2R)^2= 4πR^2



π(R)^2 will be cancelled out, gives us a ratio of 1:4.

________________


Now back to the question:


If the length is doubling, the resistance will double as well. (Direct proportion)



R of the other Cu wire= 2 x 2 = 4


However, along with the length, the diameter is increasing as well.


and we know that if diameter doubles, cross sectional area quadruples.


thus,


R of the other Cu wire= 4/4 = 1Ω

 

[fatimaw]

Resistivity of any given material depends upon three factors:

1. Length (direct proportion: more length = more resistance)




THANKS A LOT !!!!!!! cant express in words how much this helped me
if u dont mind (or any one else) can u help me answer this ... sorry

 

[whyareallnamestaken]

sin c = 1/n; where:
c is the critical angle
n is the refractive index.

sin 37= 1/n
n= 1.66

Refractive index can be defined as the speed of light in air divided by the speed of light in any other (denser) media.
thus,

1.66= 3 x 10^8/ speed of light in plastic
speed of light in plastic= 1.66 x (3 x 10^8)
= 1.8 x 10^8 m/s (option A)

 

[fatimaw]

sin c = 1/n; where:

I actually forgot abt that formula thanks a lot AGAIN!!!!