Biology; Chemistry; Physics: Post your doubts here!

[Gohar Awais]

What is diopter and power of a lens? and what kind of questions will be there regarding it?

 

[funky brat]

What is diopter and power of a lens? and what kind of questions will be there regarding it?

You are talking about GCE O'level Physics? I never heard this. :O

 

[funky brat]

http://papers.xtremepapers.com/CIE/...al O Level/Chemistry (5070)/5070_s04_qp_1.pdf
Why isn't the answer to 31st MCQ C?

 

[Dark Destination]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_s04_qp_1.pdf
Why isn't the answer to 31st MCQ C?

Really? Isn't the answer A? :O

 

[Dark Destination]

What stuff do we need to know about Electronics chapter? Those logic gates and stuff. Idk what to study, and what to leave. :/
Someone help? I have heard their is an option. And what about TRANSISTORS? Are they in the syllabus?

 

[Gohar Awais]

You are talking about GCE O'level Physics? I never heard this. :O

Yes my teacher briefly told it to our class on friday. I was just thinking about it

 

[Nafis Daiyan]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_s04_qp_1.pdf
Why isn't the answer to 31st MCQ C?

It should be A.
Galvanising prevents rusting...
Copper is less reactive than iron, so rate of rusting doesn't decrease

 

[aathil]

Umm...could some on help me out by explaining in Biology paper 6:how do I determine to number of stomata present on the surface of a whole leaf ?

Merci!

 

[funky brat]

It should be A.
Galvanising prevents rusting...
Copper is less reactive than iron, so rate of rusting doesn't decrease

Thanks. Actually I misread the question as if ways of preventing rusting were asked.

 

[Nafis Daiyan]

Thanks. Actually I misread the question as if ways of preventing rusting were asked.

Happens
See, I know chemistry

 

[funky brat]

Umm...could some on help me out by explaining in Biology paper 6:how do I determine to number of stomata present on the surface of a whole leaf ?

Merci!

Umm you can consult the book for this, the experiment would be there. Although, you can attach cobalt chloride paper to the underside of the leaf (because stomata are usually present there). The paper turns pink because of the moisture which indicates that the stomata are present that allow transpiration to occur.

 

[funky brat]

Happens
See, I know chemistry

Yeah, cousin's best friend. xD

 

[funky brat]

What stuff do we need to know about Electronics chapter? Those logic gates and stuff. Idk what to study, and what to leave. :/
Someone help? I have heard their is an option. And what about TRANSISTORS? Are they in the syllabus?

Skip logic gates, it rarely comes in the paper. Even if it comes, it is there as an either or question. You must know the stuff that is mentioned in the previous posts, view the last page.

 

[funky brat]

Really? Isn't the answer A? :O

I misread.

 

[funky brat]

Yes my teacher briefly told it to our class on friday. I was just thinking about it

What did your teacher tell you that it is in the syllabus? Can you explain briefly what this actually is?

 

[Nafis Daiyan]

Yeah, cousin's best friend. xD

You're asking questions about his past
He was simple back then...

 

[funky brat]

You're asking questions about his past
He was simple back then...

Haha. Now let's stop before somebody tells us that we are going off -topic.

 

[Nafis Daiyan]

Haha. Now let's stop before somebody tells us that we are going off -topic.

We're going off topic

 

[Gohar Awais]

What did your teacher tell you that it is in the syllabus? Can you explain briefly what this actually is?

Power of the lens, diopter (D), reciprocal of focal length measured in metres (m)
D=1/f (in metres)
Its also not in Physics Matters nor Physics federal that's why I am confused

 

[Dark Destination]

Skip logic gates, it rarely comes in the paper. Even if it comes, it is there as an either or question. You must know the stuff that is mentioned in the previous posts, view the last page.

Okay, i will!

But Rectifying diodes. Transistors. And all the other stuff. Relay. Bell. I have no idea what all this means. :/
Is this stuff mentioned in Federal physics?