Biology; Chemistry; Physics: Post your doubts here!

[TheStallion-Reborn]

what is a linear output??

 

[papajohn]

By the way, you can never connect a voltmeter in series. It is always drawn parallel across a component to get its p.d or across the cell to get the e.m.f

Even in the case when we want to find the resistance of the wire?

 

[usama321]

what is a linear output??

it means that the output is directly proportional to a changing value in the system or whatever

 

[asma tareen]

By the way, you can never connect a voltmeter in series. It is always drawn parallel across a component to get its p.d or across the cell to get the e.m.f

look beta particles are the electrons flowing so the convectional current would be opposite to it

 

[usama321]

Even in the case when we want to find the resistance of the wire?

actually we use that formula for getting resistance of a wire resistance = resistivity *l/a. The resistivity of different metal wires is different but constant i-e all copper wires would have the same resistivity

 

[Hskk]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_w12_qp_21.pdf
Q3, c i. Since we have to calculate the power SUPPLY, won't the voltmeter be across the battery?

 

[TheStallion-Reborn]

it means that the output is directly proportional to a changing value in the system or whatever

tht is whts written in the marking scheme...but WHY?? i mean, the knowledge required to answer this is the knowledge of which topic/chapter??

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_w12_qp_21.pdf
Q3, c i. Since we have to calculate the power SUPPLY, won't the voltmeter be across the battery?

it would be across the motor. This is cuz we wanna know the energy dissipated per unit charge across the motor only, and not across the whole lamp, which would include the wire's resistance too. So, using the p.d, we will use P = i.v

 

[papajohn]

ohk, so he means that beta particles as electrons, and conventional current is in the opposite direction of electrons. Thanks

Part 7b will be found by fleaming left hand rule??

 

[usama321]

tht is whts written in the marking scheme...but WHY?? i mean, the knowledge required to answer this is the knowledge of which topic/chapter??

actually i think it should be in the heat chapter. What it really means is what we have read as UNIFORM CHANGE. we have read it in the heat chapter for designing thermometer. It means that the change in length of the liquid should be the same for each 1 C increase in temperature. It should not be such that it increases 1cm for 1C and then 2 cm for the next 1 C. It should increase with the same length. When we say that it should be directly proportional, we mean that there is a constant k, in the equation. Hope you understand it better now

 

[Usama Jawad]

Precautions:
- Parallax error should be avoided. Eye placement should be correct when taking readings.
- All solutions (acids and alkalis) should be pure, impurities (such as indicators) should not be present (when preparing salts).
- The burrette should be clean and pure to avoid concentration errors.
- Care must be taken when handling/using acids/alkalis, they can cause skin burns.
- As acid (or alkali in some cases) is added to the flask, the flask should be regularly shaken to make sure that the mixture mixes properly.
- Care must be taken when adding the acid (or alkali) to the titration flask. It must be added drop by drop (not at once) so that the end point can be noted.
- All equipment, such as burrette, flask and pipette should be in proper condition. No leakages/impurities should be present.
- When the salt is prepared, the solution should be heated gently (not vigorously) to allow the water to evaporate from the solution.
Well, that's all I can think of right now. Hope that helps.

thanx

 

[Saad Mughal]

height of awesomeness! ur sources??

Common sense.

 

[Saad Mughal]

it means that the output is directly proportional to a changing value in the system or whatever

what is a linear output??

Yeah, usama321 is correct, the output is directly proportional to the changing property of the thermometric substance (just like a straight line graph).

 

[ijlalm]

Can anyone list all the transformation matrices? (including shear and stretch)

 

[usama321]

Saad Mughal though i have never seen it anywhere in any book, i just searched google and saw that Calcium carbonate is insoluble. I thought only group one and ammonium carbonates were insoluble?

 

[falcon678]

Saad Mughal though i have never seen it anywhere in any book, i just searched google and saw that Calcium carbonate is insoluble. I thought only group one and ammonium carbonates were insoluble?

dude calcium hyrdoxide is partial soluble...how can carbonate be soluble?

 

[usama321]

dude calcium hyrdoxide is partial soluble...how can carbonate be soluble?

actually i don't have a clue how this solubility thingy works, so i don't have any idea about your reasoning

 

[asma tareen]

gp 1 carbonates are soluble dude

 

[falcon678]

actually i don't have a clue how this solubility thingy works, so i don't have any idea about your reasoning

oh well....um it goes like hydroxdes r most soluble(mostly the only form aqueous solutions)...then comes oxides n then carbonates....if v comapre these three on anion side

 

[usama321]

gp 1 carbonates are soluble dude

and Ca is in group 2