Physics: Post your doubts here!

[unique840]

What exactly am I supposed to write? :s do i write this all ^

u will write that time period is twice of the original and every alternate oscillation is energized. every impulse increases energy of the oscillator and thus the amplitude

 

[zain tariq]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_43.pdf
in question number 10 part b(1) the ms says output is negative when switch is open but should'nt it be positive?plz reply asap thnx

 

[hassam]

u r ryt brother....when switch is open it shud be positive

 

[hassam]

http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w07_qp_4.pdf​

q2 a (ii)​

here wen finding separation between atoms.....okay....we calculate volume occupied by a single atom......then when taking the cube root aren't we finding the length of the cube assuming cubic atoms...how does this relate to separation between atoms....i never understand this....i mean why is the length of cubic atom also separation between atoms........well likhtay likhtay aik cheex xehn mein ayi....is it because legth of one side is same as the distance between the centres of two adjacent cubic atoms?????​

 

[hassam]

brother 1 v is the potentIal dropped across the first R AND U R Saying its the potential of non inverting input........................and k if u r ryt then what will hapeen wen switch is closed.....nothing will happen ....polarity will nt be changed.......

 

[Most_UniQue]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w07_qp_1.pdf

Q. 23 and 25

 

[hm12]

when switch open V- is 1.5v V+ is 2.0v if u take gain equal to 10^5 then Vout= 10^5(2.0-1.5)=50 000 to prevent saturation Vout=+9V
when switch is closed V- is 3.0V and V+ is 2.0V then Vout=10^5(2.0-3.0)=-100000V to prevent saturation Vout=-9V
S0 output changes from positive to negative this is what i think the answer should be

 

[hassam]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_1.pdf

Q. 23 and 25

kindly no post in A2 thread

 

[Most_UniQue]

kindly no post in A2 thread

This is As and A2 thread. Read the posts!

 

[$~SauD~$]

What is phase difference?
THanks

 

[confused123]

What is phase difference?
THanks

how much does one wave lags behind the other. one wave is equal to 2 pi radians. how much out of phase are two waves on a graph. its hard to grasp.

 

[$~SauD~$]

how much does one wave lags behind the other. one wave is equal to 2 pi radians. how much out of phase are two waves on a graph. its hard to grasp.

can you simplify even more :/ with more examples
-Thanks

 

[confused123]

i c

can you simplify even more :/ with more examples
-Thanks

i can't, you need to use some book or look for past paper questions. i can't draw a diagram here. sorry.

 

[$~SauD~$]

i c
i can't, you need to use some book or look for past paper questions. i can't draw a diagram here. sorry.

i tried that's why i ended up posting the doubt here :/

 

[Most_UniQue]

Phase difference formula is given by 2pi ( the distance between adjacent peaks/lag / lamda )

 

[confused123]

[/ATTACH]

i tried that's why i ended up posting the doubt here :/

really, use chadda's book cambridge endorsed one,
draw a graph , taking displacement on y axis and distance on x axis. draw a sin wave. the wave is 360 degree or 2 pi radians.
take points according on x- axis. take two points suppose A and B , a at start of the wave and b at the end of the wave, both being in same state of motion or at same displacement from mean position. they have a phase difference of 360 degree or 2 pi radians. just like this take any two points and read on the x axis how much they differ in radians or in degrees. this is how we calcular phase angle difference. if two waves are given on the same graph then it becomes bigger shit. :|

 

[$~SauD~$]

What about minima and maxima? what are those?

and when 2 waves meet, and theyy have like crest and trough meeting...
so when are stationary waves produced and when are destructive interference produced?

 

[confused123]

What about minima and maxima? what are those?

and when 2 waves meet, and theyy have like crest and trough meeting...
so when are stationary waves produced and when are destructive interference produced?

bring some past paper question relevant to these concepts. then i would be able to better explain.

 

[$~SauD~$]

bring some past paper question relevant to these concepts. then i would be able to better explain.

sure, i would search and post them by tomorrow
and by the way, you rock

 

[confused123]

sure, i would search and post them by tomorrow
and by the way, you rock

haha buttering hmm, no need. i will help u anyway