Biology; Chemistry; Physics: Post your doubts here!

[Saad Mughal]

should not it increase too?

When you're taking the under root of a very small value (0-1), it generally is larger than the value.

 

[usama321]

When you're taking the under root of a very small value (0-1), it generally is larger than the value.

so it depends on the situation.

100 = 5^2 R
R = 4

now
200 = I^2 4
50 = I^2
I = 7.07

 

[Saad Mughal]

so it depends on the situation.

100 = 5^2 R
R = 4

now
200 = I^2 4
50 = I^2
I = 7.07

Exactly.

 

[AhsanAfzal]

R=1500,P=0.25, then I=0.013
R=1500,P=0.1, then I=0.008.
P is decreasing with I

 

[AhsanAfzal]

....in this question

 

[Saad Mughal]

....in this question

This is confusing.

 

[usama321]

....in this question

can you tell me the answr to the first part?

 

[Saad Mughal]

....in this question

less: (likely to) burn out/blow/become too hot.
greater: (likely to) be large (in size).
The marking scheme says this. Now, we're at a dead end.

 

[usama321]

can you tell me the answr to the first part?

ok i got it

 

[Saad Mughal]

ok i got it

I've posted the answer. I'm confused.

 

[usama321]

I've posted the answer. I'm confused.

read carefully m talking about the first part of the question

 

[Saad Mughal]

read carefully m talking about the first part of the question

Ah, that's easy. Brown, green, red.

 

[usama321]

yup, i knew about the multiplier, i did not know it was supposed to be the power of 10

 

[usama321]

k i think i got it. The power rating of a resistor is not what we guys are thinking. It is actually the maximum power that the resistor can dissipate without blowing. So if the rating is low, then of course it would blow as the current and resistance remain the same. And to make the power rating high, we need to increase the size of the resistor. So if the power rating is high, we will need a bigger resistor which is a disadvantage
Saad Mughal AhsanAfzal

 

[Amnaa]

http://papers.xtremepapers.com/CIE/...al O Level/Chemistry (5070)/5070_s03_qp_1.pdf
question no. 28 and 27

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_s03_qp_1.pdf
question no. 28 and 27

27 would be A. As the cryolite is used to dissolve the ore and lower its melting point

28 A again. As more carbon is added to iron, the steel becomes stronger and brittle as well. So q is more brittle and stronger as well

 

[Amnaa]

http://papers.xtremepapers.com/CIE/...al O Level/Chemistry (5070)/5070_s05_qp_1.pdf
i've done this paper..
question no. 13, 18, 19, 22, 23, 33, 37 and 38 were wrong ! i got 32/40.. bad attempt :/

 

[Amnaa]

27 would be A. As the cryolite is used to dissolve the ore and lower its melting point

28 A again. As more carbon is added to iron, the steel becomes stronger and brittle as well. So q is more brittle and stronger as well

can you please explain me what is brittle.. i thought the material which is not strong enough..

 

[pinkywinkypuffy]

brittles means that,that stuff having hardness and rigidity but little tensile strength; breaking

can you please explain me what is brittle.. i thought the material which is not strong enough..

readily with a comparatively smooth fracture, as glass.

easily damaged or destroyed

can you please explain me what is brittle.. i thought the material which is not strong enough..

 

[usama321]

can you please explain me what is brittle.. i thought the material which is not strong enough..

example of brittle can be anything which breaks on bending, like glass, if you try to bend it it would break. It is like the opposite of malleable