Physics, Chemistry and Biology: Post your doubts here!

[omaaaar]

No problem, feel free to ask anytime.

I will keep posting my doubts as I am solving the papers

 

[omaaaar]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w06_qp_1.pdf
Q9 i didnot get the question
Q14 in evaporation a the high energy particles leave the liquid so the remaining molecules should be closer
Q16 i didnot get anything in this question so could you elaborate it a bit
Q33 i want to know that why cant the answer be C

 

[GorgeousEyes]

Please - jun09 v.12 no.22 , why it's not D ?
no.28 --> if i was asked to arrange them , what will be the order?
- Nov09 v.12 no.16 , How it goes down ? i think it should be increase ? as pressure increase?
no.23 , why it's not D
-June2012 v.12 no.23
-Nov2010 v.12 no.29 , Resistance decreases so it have more voltage ?
no.4 also can't get it.
-Jun2012 v.12 no.18 why not B ?
no.33 also can't get it .
-June2012 v.13 no.18
-Nov012 v.12 no.25 .
-Nov012 v.13 n0.13

I really neeed help in those Anyone ?

 

[Othman]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w06_qp_1.pdf
Q9 i didnot get the question
Q14 in evaporation a the high energy particles leave the liquid so the remaining molecules should be closer
Q16 i didnot get anything in this question so could you elaborate it a bit
Q33 i want to know that why cant the answer be C

q9) Is asking what type changes into heat energy to heat the water to become steam and move the turbines, nuclear energy is first transformed into heat to produce steam. So it is B.
q14) You got this wrong it is the water evaporating not the remaining water, so they are semiclose then they become far, which is C.
q16) You should know the fixed points used to calibrate the thermometer, these are zero and 100 Celsius. 100 is the steam which is boiling water and the zero is the melting pure ice. So 22-2 = 20 this is the 100 Celsius range. Each CM is 5 Celsius, because 22-2=20, 100/20= 5 for each CM. 8-2=6, 6*5=30 Celsius

q33) 33 is not C, it is A because thicker wires have less resistance, when current is blocked heat is produced thus reducing the resistance reduces heat produces.

 

[Othman]

Please - jun09 v.12 no.22 , why it's not D ?
no.28 --> if i was asked to arrange them , what will be the order?
- Nov09 v.12 no.16 , How it goes down ? i think it should be increase ? as pressure increase?
no.23 , why it's not D
-June2012 v.12 no.23
-Nov2010 v.12 no.29 , Resistance decreases so it have more voltage ?
no.4 also can't get it.
-Jun2012 v.12 no.18 why not B ?
no.33 also can't get it .
-June2012 v.13 no.18
-Nov012 v.12 no.25 .
-Nov012 v.13 n0.13

I really neeed help in those Anyone ?

Very hard to answer them as you didn't post the links the download links for the years, I will try.

 

[Othman]

Please - jun09 v.12 no.22 , why it's not D ?
no.28 --> if i was asked to arrange them , what will be the order?
- Nov09 v.12 no.16 , How it goes down ? i think it should be increase ? as pressure increase?
no.23 , why it's not D
-June2012 v.12 no.23
-Nov2010 v.12 no.29 , Resistance decreases so it have more voltage ?
no.4 also can't get it.
-Jun2012 v.12 no.18 why not B ?
no.33 also can't get it .
-June2012 v.13 no.18
-Nov012 v.12 no.25 .
-Nov012 v.13 n0.13

I really neeed help in those Anyone ?

jun09 v.12 no.22 , why it's not D ?= It is C because a change in direction takes place.
Q28 = B>D>A>C

Nov09 v.12 no.16 , How it goes down ? i think it should be increase ? as pressure increase?
no.23 , why it's not D

16)Yes pressure increases that is why the level goes down as the air pushes the liquid down
23) It is C, you have to draw it to answer it.

-June2012 v.12 no.23
D, the trick here is that they want the image position not the place where the ray reflects.

Nov2010 v.12 no.29 , Resistance decreases so it have more voltage ?
no.4 also can't get it.

Q29) It is C, use the rule ( R / total R ) * Voltage
20/30 * 12 = 8 and 10/30 * 12 = 4
So on V1 increases and V2 decreases, it is a potential divider that divides the voltage.

4) D, Barometer is used to measure the atmospheric pressure.



I give up I can't keep searching for the papers sorry

 

[GorgeousEyes]

jun09 v.12 no.22 , why it's not D ?= It is C because a change in direction takes place.
Q28 = B>D>A>C

Nov09 v.12 no.16 , How it goes down ? i think it should be increase ? as pressure increase?
no.23 , why it's not D

16)Yes pressure increases that is why the level goes down as the air pushes the liquid down
23) It is C, you have to draw it to answer it.

-June2012 v.12 no.23
D, the trick here is that they want the image position not the place where the ray reflects.

Nov2010 v.12 no.29 , Resistance decreases so it have more voltage ?
no.4 also can't get it.

Q29) It is C, use the rule ( R / total R ) * Voltage
20/30 * 12 = 8 and 10/30 * 12 = 4
So on V1 increases and V2 decreases, it is a potential divider that divides the voltage.

4) D, Barometer is used to measure the atmospheric pressure.



I give up I can't keep searching for the papers sorry

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s12_qp_13.pdf
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s12_qp_12.pdf
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w12_qp_12.pdf
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w12_qp_13.pdf

Thank youuu !

 

[omaaaar]

papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Physics%20(0625)/0625_w03_qp_1.pdf
how come the answer for question number 14 is D
and for question number 39 C

The answer for 14 is D as the solid particles are not stationery they also vibrate at their fixed positions and molecules of gases and liquids move
The answer for 39 is C as the question is asking about the particles in the nucleus and there are no electrons in the nucleus so they are 0 as they revolve around the atom
Hope you understood

 

[Othman]

papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Physics%20(0625)/0625_w03_qp_1.pdf
how come the answer for question number 14 is D
and for question number 39 C

14) They move " vibrate" they are not stationary so it is D
39) Keyword is nucleus, you have to read the question carefully. The nucleus has 2 neutrons and 2 protons. Very tricky question.

 

[omaaaar]

q9) Is asking what type changes into heat energy to heat the water to become steam and move the turbines, nuclear energy is first transformed into heat to produce steam. So it is B.
q14) You got this wrong it is the water evaporating not the remaining water, so they are semiclose then they become far, which is C.
q16) You should know the fixed points used to calibrate the thermometer, these are zero and 100 Celsius. 100 is the steam which is boiling water and the zero is the melting pure ice. So 22-2 = 20 this is the 100 Celsius range. Each CM is 5 Celsius, because 22-2=20, 100/20= 5 for each CM. 8-2=6, 6*5=30 Celsius

q33) 33 is not C, it is A because thicker wires have less resistance, when current is blocked heat is produced thus reducing the resistance reduces heat produces.

Thanks for the help

 

[Othman]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s12_qp_13.pdf
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s12_qp_12.pdf
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w12_qp_12.pdf
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w12_qp_13.pdf

Thank youuu !

M/J 2012 V12,
Q18 ) Wood is an insulator, it so the side P is the lowest temp as no heat is reaching it and the hottest is Q as no heat is being conducted like R. So it is A. Think of it as a pipe that has a leakage at one end and one that doesn't which one will have more water ?

Q33) The same as the old potentialdivider question 20/30 * 12 = 8 which is C.


June2012 v.13 no.18
It took 80J to raise it 20 Celsius so how much to change it by 10 ? 80/2 = 40 J which is A. and it decreases as the temp falls.


Nov012 v.12 no.25 .

It is C, as A is the direction of flow, B is the wavelength and D is the plane surface.

Nov012 v.13 n0.13


This is the hardest question I saw in the past papers, it is C;
P=F/A
If there were an option were an option where force is different it would be correct but here the pressure is the same because the depth is the same.

 

[omaaaar]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s07_qp_1.pdf
Q20 why the answer is C not B,and as the waves travel faster in deep water so the ditance between them will increase or decrease
Q22 dont know anything about this question
Q27 why is the answer B ,will the compass point in the direction from north to south that is the magnetic field or it will point at the north pole of the magnet as all compasses point towards the north pole
Q34 why is the answer C that is fire ,not B electric shock

 

[GorgeousEyes]

M/J 2012 V12,
Q18 ) Wood is an insulator, it so the side P is the lowest temp as no heat is reaching it and the hottest is Q as no heat is being conducted like R. So it is A. Think of it as a pipe that has a leakage at one end and one that doesn't which one will have more water ?

Q33) The same as the old potentialdivider question 20/30 * 12 = 8 which is C.


June2012 v.13 no.18
It took 80J to raise it 20 Celsius so how much to change it by 10 ? 80/2 = 40 J which is A. and it decreases as the temp falls.


Nov012 v.12 no.25 .

It is C, as A is the direction of flow, B is the wavelength and D is the plane surface.

Nov012 v.13 n0.13


This is the hardest question I saw in the past papers, it is C;
P=F/A
If there were an option were an option where force is different it would be correct but here the pressure is the same because the depth is the same.

Thanks a million ,

May Allah ​

bless ​

you with success ! ​

​

 

[Othman]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s07_qp_1.pdf
Q20 why the answer is C not B,and as the waves travel faster in deep water so the ditance between them will increase or decrease
Q22 dont know anything about this question
Q27 why is the answer B ,will the compass point in the direction from north to south that is the magnetic field or it will point at the north pole of the magnet as all compasses point towards the north pole
Q34 why is the answer C that is fire ,not B electric shock

q20) In deep water they are faster so the distance increases. in B there are more wavefronts so obviously they are slower which is wrong.
q22) B, simple math as the normal makes a 90 angle so 90-30 = 60, the angle for mirror X is the same for mirror Y.
q27) Magnetic field is from the north to the south, so the correct compass is B.
q34) As I said current produces heat, heat causes fire. Danger it must be fire or electric shock but current doesn't electrocute u as the wires are insulated. So it is C.

 

[Othman]

I'm off for now, msg me so you can make sure that I see your questions.

 

[Othman]

Thanks a million ,

May Allah ​

bless ​

you with success ! ​

​

no problem

 

[nononona]

Q2- if it had constanr acceleration it would keep going up and wouldnt come down.
Q8- F=ma so a=F/m F and m are constant so a will also be constant.
Q11- mercury is denser than water so it wont move much so h will be less

thanks a lot

 

[omaaaar]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
Q21 why the answer is B
Q23 didnot understand could someone explain

 

[GorgeousEyes]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
Q21 why the answer is B
Q23 didnot understand could someone explain

Q21 is B as this line is the undisturbed position .
I don't knw how to explain Q23 :/

 

[Gehad Mohamed]

Could someone please help me in Q 37 & 15 in http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s08_qp_1.pdf