Physics: Post your doubts here!

[Mattman]

how do decide how many SFs to use when writing down the awnser and its uncertainty?

 

[leosco1995]

well, here, you have to answer in reference to the graph, not by interpreting from the equation. you can see that in the graph, as V increases beyond 1.6 the power dissipation decreases.

Yeah, didn't read the question properly. :\ Thanks.

 

[Most_UniQue]

Any help would be really appreciated Part B, C(i)(iv)

 

[Most_UniQue]

Btw all the answers must be in 3 SF?

 

[Hassi123]

CAN SOMEONE PLEASE HELP ME WITH PHASE DIFFERENCE? WHAT IS IT??? (SORRY FOR CAPITAL LETTERS IM WORRIED AS SHIT)

 

[TheMan123]

When I was doing this paper as revision:http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s10_qp_21.pdf
I noticed question 5.b)ii) does not have an answer on the mark scheme, so can anyone tell me the answer?

 

[littlecloud11]

Any help would be really appreciated Part B, C(i)(iv)



View attachment 10897
View attachment 10899

View attachment 10900

ci) For the stationary wave the particles between two consecutive nodes or 2 consecutive antinodes vibrate in the same phase. therefore, they have no phase difference between them. the answer will be 0.

iv) the wave will be a straight horizontal line over the dotted line. For a stationary wave there is no onward motion of disturbance from one particle to the adjoining particle, so beyond a particular instant of time the displacement of all the particles is 0.

a1) the diagram is below. for a wave s = f x lamda, therefore s = (1/T) x lamda so, lamda = s x T
the speed is same for both the first and the second wave, as T changes by .25 the wavelength also shifts by .25, which is 20cm here. thus the second wave will be 20 cm to the right of the first.

 

[alim]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s03_qp_2.pdf
Q4a(ii)
why the maximum brightness decreases and seperaation increases in 1 n 2???

 

[00tanveer]

Anyone got any notes on potentiometers?? Please it would really help if anyone posted any link!! Thank you!

 

[Tabi Sheikh]

When I was doing this paper as revision:http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_21.pdf
I noticed question 5.b)ii) does not have an answer on the mark scheme, so can anyone tell me the answer?

 

[alim]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s03_qp_2.pdf
Q4a(ii)
why the maximum brightness decreases and seperaation increases in 1 n 2???

any1???....
also have problem in http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w03_qp_2.pdf
Q4b ....how to find the spacing of the lines of the grating???...

 

[Tabi Sheikh]

please answer the question with explanation

 

[Tabi Sheikh]

any1???....
also have problem in http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w03_qp_2.pdf
Q4b ....how to find the spacing of the lines of the grating???...

you will just divde 1m/5.8*10^5 and the answer is 1.72*10^-6 because there are 5.8*10^5 lines in 1 meter

 

[Tabi Sheikh]

Actually, D can't be labeled to the right if the metal plate, because the field lines are getting closer, so the strength of the field is increasing.

yes you r right the field lines are getting toward the sphere
thanks for correction

 

[Most_UniQue]

ci) For the stationary wave the particles between two consecutive nodes or 2 consecutive antinodes vibrate in the same phase. therefore, they have no phase difference between them. the answer will be 0.

iv) the wave will be a straight horizontal line over the dotted line. For a stationary wave there is no onward motion of disturbance from one particle to the adjoining particle, so beyond a particular instant of time the displacement of all the particles is 0.

a1) the diagram is below. for a wave s = f x lamda, therefore s = (1/T) x lamda so, lamda = s x T
the speed is same for both the first and the second wave, as T changes by .25 the wavelength also shifts by .25, which is 20cm here. thus the second wave will be 20 cm to the right of the first.

Oh okay so if it wasnt a stationary wave then it wud be 180* right?

For a1 I got it but how does it start from 20?

 

[littlecloud11]

View attachment 10909please answer the question with explanation

S= ut + 1/2 a t^2
for t1 sec distance traveled = 0 + 1/2 g t1^2
for t2 sec distance traveled = 0 + 1/2 g t2^2

so the difference = 1/2 g t2^2 - 1/2 g t1^2
that's D

 

[Tabi Sheikh]

thanks

 

[Silent Hunter]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s07_qp_2.pdf

need help in question 6 part (a) (ii) Why are we using total emf here? Its only asking about the battery ...... am confused

 

[Most_UniQue]

No, it wouldn't. for the wave to have a phase difference if 180* the difference between them has to be 1/2 the wavelength. here, it if were a moving wave the phase difference would be approx. 45* that is 1/8 the wavelength.

The initial wave starts from zero, and by then the second wave has already traveled 1/4 of the wavelength, that is 20m. So, it starts from 20.

Oh ok gt it Tnx

 

[Silent Hunter]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s07_qp_2.pdf

need help in question 6 part (a) (ii) Why are we using total emf here? Its only asking about the battery ...... am confused