Biology; Chemistry; Physics: Post your doubts here!

[TheStallion-Reborn]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf question 13..why is A the answr??

 

[Zuhsid]

thank you man

Welcome bro....

 

[TheStallion-Reborn]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf question 13..why is A the answr??

and for question 15...how can it be D?? Saad Mughal do we have yet another error?

 

[farhan141]

I

dude...ur denying ur ownself. pressure is inversely proportional to volume. agreed. so that mean if temperature is directly proportional to volume, it has to be inversely proportional to pressure. usama321 ur thoughts??

Im not sure if Pressure is directly proportional to volume or not.

 

[Zuhsid]

dude...ur denying ur ownself. pressure is inversely proportional to volume. agreed. so that mean if temperature is directly proportional to volume, it has to be inversely proportional to pressure. usama321 ur thoughts??

See..... Temperature, volume and pressure are connected by the formula: "Temperature= Pressure x Volume"..... so if u rearrange the values and take one of them constant at a time, ull see how they satisfy the 3 formula....

 

[usama321]

dude...ur denying ur ownself. pressure is inversely proportional to volume. agreed. so that mean if temperature is directly proportional to volume, it has to be inversely proportional to pressure. usama321 ur thoughts??

well if you increase the temperature of a gas, the space between the molecules increases, meaning it is directly proportional.

if you increase the temperature of a gas, the pressure decreases, because the volume of the gas increases. But if the volume is kept constant, then increasing temp increases pressure,

 

[asma tareen]

and for question 15...how can it be D?? Saad Mughal do we have yet another error?

its ans is correct 40=x-2/22-2 * 100 (x is length ov liquid) solve it u'll get 10

 

[Saad Mughal]

and for question 15...how can it be D?? Saad Mughal do we have yet another error?

It is D. 40 = x - 2/20 * 100
0.4 * 20 = x - 2
x = 8 + 2 = 10 cm

 

[Zuhsid]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf question 13..why is A the answr??

Coz pressure and volume are inversely proportional, thus by that they are connected by the formulae "Pressure=K/Volume", where k is the temp....... so u get a constant value of K in B, C and D..but not A...so A is ur answer...!!

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf question 13..why is A the answr??

pressure * volume of the last three is constant , however the first one has different

 

[qasim9]

what does a capacitor do ?
when do we use right hand rule and left hand rule ?
plz do tell..

 

[usama321]

Coz pressure and volume are inversely proportional, thus by that they are connected by the formulae "Pressure=K/Volume", where k is the temp....... so u get a constant value of K in B, C and D..but not A...so A is ur answer...!!

k is not the temperature i think. It is just a constant. The formula is only applicable if there is no change in temperature.

 

[farhan141]

what does a capacitor do ?
when do we use right hand rule and left hand rule ?
plz do tell..

Capacitor temporarily stores current.

Right Hand Grip Rule is used to find direction of current and direction of magnetic field.

 

[TheStallion-Reborn]

what does a capacitor do ?
when do we use right hand rule and left hand rule ?
plz do tell..

forget about right hand rule not in our syllabus..left hand rule is used at many instances...where any of the following is required whilist the other two are given,,force on wire, direction of current and direction of magnetic field. a capacitor stores charges. it is also used to determine the force on alpha particles,,for beta, find the directino for alpha and make it opposite, no need to confuse urself with other methods

 

[bubbles1997]

A potential divider works this way, if the resistance increases, the voltage also increases; if the resistance decreases, the voltage decreases.

Aoa. Do you have guess paper?

 

[Ishrar Afrida]

5 b (i) (ii) Help!!

 

[Saad Mughal]

Aoa. Do you have guess paper?

No, but I'm making a thread that you can read.

 

[Zuhsid]

5 b (i) (ii) Help!!

At point P, draw a tangent to the optic fiber, and at the same point, draw a perpendicular line, which is the normal...... the angle between this line and the the line of incidence is the angle of incidence.....
What happens there is .... Total Internal reflection, such that the incident ray strikes the optic fiber wall at an angle higher than the critical angle(of the fiber), thus the ray reflects back and does not refract..!!!
Hope it helps....

 

[asma tareen]

No, but I'm making a thread that you can read.

6ag me if u made a thread

 

[ayesha121997]

what does a capacitor do ?
when do we use right hand rule and left hand rule ?
plz do tell..

flemings right hand rule is used when u r asked to find direction of current (in ac generater)
flemings left hand rule is used when u r sked to find motion (force)...
right hand grip rule is used to find direction of current and magnetic field......