Post Your AS LEVEL PHYSICS PAPER 2 DOUBTS

[leosco1995]

Harmonic is the first ever wave thing produced so over here it is an antinode and node which lambda/4 and this in other words is also called the fundamental frequency meaning lowest frequency

Still, kinda don't get it. I read up some stuff on harmonics and it sort of understand the concept but I don't understand how you got lambda/4.

 

[applepie1996]

Still, kinda don't get it. I read up some stuff on harmonics and it sort of understand the concept but I don't understand how you got lambda/4.

didn't u draw da diagram dey asked 2 dats how i got it

 

[leosco1995]

didn't u draw da diagram dey asked 2 dats how i got it

I did. I drew an anti-node at the open end of the tube, a node at the piston end and a 2nd anti-node and node in the middle of them like this:

(open end of tube) A...N...A...N (end of tube)

..I know the first harmonic has the lowest frequency but I thought it's supposed to be 0.5 lambda.. how did you get 0.25 lambda?

 

[leosco1995]

..Oh I think I get it now, it's the distance between the first anti-node and node.. right?

 

[applepie1996]

..Oh I think I get it now, it's the distance between the first anti-node and node.. right?

yup

 

[Shouly]

for da first one S1 is opened and it is the main switch so if it is open the power in the whole circuit will also be zero
for da second one current always takes the path with the least resistance in dis case it goes through the loop with th B heater so power is 240^2/38.4=1.5kw
u'll take sum of the resistance as i said current always takes the path with the least resistance in dis case it goes through the loop with th B heater and the C heater which are parallel 2 each other so resistance on parallel is 38.4 x 38.4/38.4 + 38.4=19.2 so power = voltage^2/resistance=240^2/19.2=3kw
for da third onewell this pretty easy as it is a normal series circuit so u add the resistance 38.4+38.4=76.8 then u find the power=240 squared /76.8=0.75kw
u find total resistance first which is 76.8 x 38.4/76.8 + 38.4=25.6 now find power 240 squared /25.6 =2.25kw

Sorry but I didnt quite understand, what is the path with the least resistance :| ? How would I know which path has the least resistance? current here is anticlockwise correct?

 

[applepie1996]

Sorry but I didnt quite understand, what is the path with the least resistance :| ? How would I know which path has the least resistance? current here is anticlockwise correct?

who cares path with the least resistance will include the path with only one heater imagine the current following through both heaters and one heater where is resistance less one heater or two one right ??? so it goes round da loop with the heater B

 

[Shouly]

Hey everyone, in my answers I always get them right its just that I dont get them in the exact figure they state in the marks scheme. for example I calculated a density & its uncertainity as :4.9x10^-7 +- 3.97x10^-8
While the answer in the mark scheme was 3.9x10^-7 +- 0.4x10^-7
Will they give me the mark for my answer? And if not please someone tell me the amount of significant figures or how im supposed to give my numerical answers usually, exam's tomorrow so answer asap please and thankyou!

 

[Shouly]

who cares path with the least resistance will include the path with only one heater imagine the current following through both heaters and one heater where is resistance less one heater or two one right ??? so it goes round da loop with the heater B

Thankyou so much!

 

[applepie1996]

Hey everyone, in my answers I always get them right its just that I dont get them in the exact figure they state in the marks scheme. for example I calculated a density & its uncertainity as :4.9x10^-7 +- 3.97x10^-8
While the answer in the mark scheme was 3.9x10^-7 +- 0.4x10^-7
Will they give me the mark for my answer? And if not please someone tell me the amount of significant figures or how im supposed to give my numerical answers usually, exam's tomorrow so answer asap please and thankyou!

for the final answers its usually 2 or 3s.f.and if u need to solve a question using an answer u get use 5 s.f.

 

[applepie1996]

Thankyou so much!

ur welcome

 

[confused123]

post your doubts and i'll try and clear them

kindly help...
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s10_qp_22.pdf
q.2 c , 6 d , 7 b ii (1)

 

[applepie1996]

kindly help...
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_22.pdf
q.2 c , 6 d , 7 b ii (1)

q2c
it is less dense so there will be more effect of air resistance so speed decreases therefore the gap between the images will be lesser as it will be falling slower than the first ball.
6d
resistance between A and C not equal to resistance between C and B
current in wire AC × R is not equal to current in wire BC × R(i dont noe wat is there 2 explain in dis sum)
7b)ii)i dunt get u it

 

[Rakayz]

can u explain the whole of this question? w07_qp_2----- question 5 a) b) c)

Thanks!

 

[confused123]

q2c
it is less dense so there will be more effect of air resistance so speed decreases therefore the gap between the images will be lesser as it will be falling slower than the first ball.
6d
resistance between A and C not equal to resistance between C and B
current in wire AC × R is not equal to current in wire BC × R(i dont noe wat is there 2 explain in dis sum)
7b)ii)i dunt get u it

thanks a bunch. some more:-

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w09_qp_22.pdf
Q.6 c) resistance of
each lamp / Ω in parallel and combined resistance in parallel . i didn't got these two values right.

 

[BHAI]

can anybody list all the estimations important for as level physics p2 means tomorrow's exam .... ASAP ??

 

[applepie1996]

can u explain the whole of this question? w07_qp_2----- question 5 a) b) c)

Thanks!

a)it is lagging pie/3 times so u start the drawing lyk dat and den intensity calculation??????
b)λ = ax / D this is the formula u shuld noe it by heart
540 × 10–9 = (0.700 × 10–3 x) / 2.75
=2.12 x 10^-3 m
=2.12 mm
c)i)the brighter fringes become brighter as more thickness to deflect through and darkness doesn't increase so no change
ii)increase in gap soo more place for light to place through so more fringes hence separation between them decreases

 

[USMAN Sheikh]

DERE I SOLVED UR DOUBTS U CAN CHECK THEM OUT

i want u to make the graphs its not clear to me plsss yar

 

[confused123]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w11_qp_23.pdf
7 b, c

 

[applepie1996]

thanks a bunch. some more:-

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w09_qp_22.pdf
Q.6 c) resistance of
each lamp / Ω in parallel and combined resistance in parallel . i didn't got these two values right.

luk at the graph when the lamp is 3volts the current is 0.15 A so resistance is 20 ohms and combined resistance is 10 ohms