A2 Physics | Post your doubts here

[RGBM211]

I know its a kiddish question but mmm how to draw a)
forget

 

[leadingguy]

View attachment 8229

I know its a kiddish question but mmm how to draw a)
forget

the light ray wil travel in straight line and wil reflect the the wall and wil go down at an angle then wil again reflect the downward wall and move upwards and wil do the same to travel to the other side of of the fibre.

the core should be narrow to reduce energY loss as if the core is thicker the light ray has to travel more so enrgy wil be lost

 

[RGBM211]

the light ray wil travel in straight line and wil reflect the the wall and wil go down at an angle then wil again reflect the downward wall and move upwards and wil do the same to travel to the other side of of the fibre.

the core should be narrow to reduce energY loss as if the core is thicker the light ray has to travel more so enrgy wil be lost

Can yu plz show ?

 

[omg]

well for finding displacement from the mean position in a simple harmonic motion.

we use the formula X= X0sinwt (this is used when no displacement took place at time, t = o ) means x=o at t=o.
where As
we use the formula X = Xocoswt (this is used when no displacement took place at time, t = o ) means x=Xo at t=o.

so both formulas are correct fr calculating displacement, the thing is that they r 2 b Used at diff. occasions.

sinwt will be used when the graph is starting frm origin( o, 0)
coswt will be used when the graph is starting frm maximum displacement ( 0, Xo) hope u gt it??

YES , THANKS

 

[omg]

w07 q1 part b (ii) and s08 q3 part (c)(ii) PLEASE HELP (idk sth is wrong wid my pdf reader im nt able to open the ppr dats y couldnt giv the links)

 

[Kawshiklfc]

Please help I got a problem in a paper 53 (paper 5) May/June 2011 physics.i having difficulties in both questions.Can somebody explain to me in details about the answers.Please help.

 

[maleeha123]

plz help me with Q 1- (iii) about meteorite........

 

[smzimran]

http://www.xtremepapers.com/community/threads/a2-physics-post-your-doubts-here.13317/page-11
Anyone plz solve my question on this page
Thanks

 

[Hammad Siddiqi]

the light ray wil travel in straight line and wil reflect the the wall and wil go down at an angle then wil again reflect the downward wall and move upwards and wil do the same to travel to the other side of of the fibre.

the core should be narrow to reduce energY loss as if the core is thicker the light ray has to travel more so enrgy wil be lost

No, The reason it will lose energy does not depend upon travelling more distance... The reason is because of angle... Light ray, when it exceeds a certain degree of Angle from normal, is reflected.. The reflection is called Total Internal Reflection... if TIR doesnot occur, the light will be refracted and energy will be lost..

 

[MindStealth]

View attachment 8229

I know its a kiddish question but mmm how to draw a)
forget

I think this is about it, you won't need more accurate drawing just for 1 mark.

 

[leadingguy]

No, The reason it will lose energy does not depend upon travelling more distance... The reason is because of angle... Light ray, when it exceeds a certain degree of Angle from normal, is reflected.. The reflection is called Total Internal Reflection... if TIR doesnot occur, the light will be refracted and energy will be lost..

ya U are rite soRRy didn't pondered lite jane waLi thi na

 

[Mustehssun Iqbal]

Assalamu alaikum,
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w06_qp_4.pdf
Pls solve Q.6 , part c(2 ) ;
Pls explain why it's V( nought ) used instead of Vr.m.s.?? Thanks

 

[MindStealth]

do you know topic of practicls?

Don't try to discuss such stuff or ask such questions on the forums. First of all no one would really know the topics and if someone somehow knows and tells you, you both will get your paper cancelled probably.

 

[alphabravocharlie]

Assalamu alaikum,
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w06_qp_4.pdf
Pls solve Q.6 , part c(2 ) ;
Pls explain why it's V( nought ) used instead of Vr.m.s.?? Thanks

Don't we always use V( nought ) when calculating the energy stored in a capacitor

 

[alphabravocharlie]

Q-Explain why a capacitor stores energy but not charge?

 

[smzimran]

Q-Explain why a capacitor stores energy but not charge?

AoA,
Where did you get this question brother?
CApacitor's main work is to store charge!

 

[alphabravocharlie]

AoA,
Where did you get this question brother?
CApacitor's main work is to store charge!

WS,
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s11_qp_42.pdf
Q 3a

 

[smzimran]

WS,
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_42.pdf
Q 3a

Since there are two parallel plates storing charge, the capacitor stores charge but does not stores net charge as it is cancelled out or balanced!
It is just like a body moving with constant speed, it experiences force but no resultant force, so as to that sometimes we say that it experiences no force!!!
Hope you got the point.

 

[alphabravocharlie]

Since there are two parallel plates storing charge, the capacitor stores charge but does not stores net charge as it is cancelled out or balanced!
It is just like a body moving with constant speed, it experiences force but no resultant force, so as to that sometimes we say that it experiences no force!!!
Hope you got the point.

Yeah got it, thanks/Jazakallah

 

[RGBM211]

The linear attenuation (absorption) coefficients of bone and of soft tissues surrounding the bone are 2.9 cm^-1 and 0.95 cm^-1 respectively.A parallel beam of X-rays is incident,seperately on bone of thickness 3.0cm and on soft tissue of thickness 5.0cm.
Calculate the ratio:

intensity of transmitted through bone​

intensity of transmitted through soft tissue​

​

mmm getting the answer as 0.019 whereas the answer should be 0.19 can someone try ?​