Post Your AS LEVEL PHYSICS PAPER 2 DOUBTS

[applepie1996]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_23.pdf

question 6 (c)(iv) and in question 5 (b)(ii) why are we considering the parallel circuit resistors? why not the series one? is the reason cuz that in parallel we have same pd across each resistor?

wat u said bout question 5 is correct but it'll a little time for me 2 understand question 6 and wen i do i'll tell u

 

[Silent Hunter]

wat u said bout question 5 is correct but it'll a little time for me 2 understand question 6 and wen i do i'll tell u

okay thank you

 

[applepie1996]

How did you get the values of x2 and x1.. I don't get that part.

oh ok
x2 - x1 this is actually being used to calculate the extension
the original length if the spring b4 being pushed is 4.5cm which is x1
so when the trolley is moved 1.5cm one of the spring will have their length increased 1.5cm which is 4.5+1.5=6cm and the oder side decreased 4.5-1.5=3cm
so x2 = 3 and 6 cm

 

[vita199]

how are we suppose to draw the nodes and the antinodes in the tube in may/2010/22??and how do we how know how many to draw..i mean in the question it says on bang doesnt that mean only one node??

 

[Rakayz]

hey applepie1996 can u explain to me with detail what is:
1) phase?
2) path difference?
3) Super position?
4) Interference?

Can u also tell me how to use them according to the questions....these r the topics i never understand :S

Thanks!!

 

[applepie1996]

how are we suppose to draw the nodes and the antinodes in the tube in may/2010/22??and how do we how know how many to draw..i mean in the question it says on bang doesnt that mean only one node??

lambda=60cm so the lenght of the tube is 45cm cross multiply and u get 3/4lambda dat is wat u draw on the figure and since it is a closed end it will begin with antinode and end wid node

 

[applepie1996]

hey applepie1996 can u explain to me with detail what is:
1) phase?
2) path difference?
3) Super position?
4) Interference?

Can u also tell me how to use them according to the questions....these r the topics i never understand :S

Thanks!!

1)phase
The two turning wheels of a bicycle are cyclic events - if markers (such as the air valves) are used and both set to the top of their wheels .. these markers will rotate in-phase with each other as the bicycle moves (given that the two wheels have the same radius). The markers will reach the same stage in their rotations at the same times (eg arrive at the bottom - their lowest point, together .. etc.
If one of the wheels is advanced by 1/4 turn -so that it's marker is mid-way down when the other is at the top .. then the rotations are not in-phase with each other even though they both have cyclic motion of the same frequency. The motion of the two markers has a 1/4 cycle phase difference.

Phase angle is a way of measuring the difference, for a given stage, between two cyclic events - the difference is expressed as an angle with 360º (or 2π radians) representing a full cycle.
A 1/4 cycle difference is a 90º phase difference, 180º for a 1/2 cycle difference ..etc. The phase angle can be used to indicate if the difference is a lead or a lag by using + or - angles values.

 

[applepie1996]

hey applepie1996 can u explain to me with detail what is:
1) phase?
2) path difference?
3) Super position?
4) Interference?

Can u also tell me how to use them according to the questions....these r the topics i never understand :S

Thanks!!

path difference
PATH difference is pretty much the same, except instead of giving the difference in degrees/radians, u give the answer in terms of lambda

 

[applepie1996]

hey applepie1996 can u explain to me with detail what is:
1) phase?
2) path difference?
3) Super position?
4) Interference?

Can u also tell me how to use them according to the questions....these r the topics i never understand :S

Thanks!!

superposition
if suppose there were two or more waves present in a place, then the resultant will also be a wave with the amplitude being the sum of the amplitudes of individual waves.
like if you were given 2 chocolates by a person and another gives you 5 so u wuld have 7 in a similar way in superposition the waves amplitude gets added

the wave need not even have anything in common, they may have everything different but at a specific time instant if the waves have individual amplitudes A1 , A2 , A3 etc the resultant is A1+A2+A3 etc..!!

 

[applepie1996]

hey applepie1996 can u explain to me with detail what is:
1) phase?
2) path difference?
3) Super position?
4) Interference?

Can u also tell me how to use them according to the questions....these r the topics i never understand :S

Thanks!!

interference
Wave interference is the interaction between waves that meet. Like if there are two waves travel at the opposite direction, they gotta pass through each other. There are 2 types of wave interference : constructive and destructive.

Constructive interference is the interference that occurs when waves combine to make a wave with a larger amplitude (distance from the crest or trough to their rest position). Two waves approach each other. The crest's new amplitude is the sum of the amplitude of the original crests. After meeting the waves continue as if they had not meet.

Destructive interference is when two waves combine to make a wave with a smaller amplitude. It's ALWAYS occur when the crest of one wave overlaps the trough of the other wave. The only with the larger amplitude always takes the shape of the interference. If the original waves had equal amplitude, then the crest and the trough can completely cancel each other out

And unlike superposition Interference does require conditions to be carried out like
1)both waves should be of the same type
2)should meet at a point
3)they should have no phase difference

 

[applepie1996]

hey applepie1996 can u explain to me with detail what is:
1) phase?
2) path difference?
3) Super position?
4) Interference?

Can u also tell me how to use them according to the questions....these r the topics i never understand :S

Thanks!!

HOPE U GET IT !!!!!

 

[USMAN Sheikh]

urgent help need on graphs only graphs question Q no 6 part b and c (4) plssssssss

 

[leosco1995]

The change ∆V in the volume V of some water when the pressure on the water increases
by ∆p is given by the expression ∆p = 2.2 × 10^9 ∆V / V,
where ∆p is measured in pascal.
In many applications, water is assumed to be incompressible.
By reference to the expression, justify this assumption.

Please explain it.

 

[applepie1996]

urgent help need on graphs only graphs question Q no 6 part b and c (4) plssssssss

that your new graph should be about quarter the size of your old one

 

[applepie1996]

The change ∆V in the volume V of some water when the pressure on the water increases
by ∆p is given by the expression ∆p = 2.2 × 10^9 ∆V / V,
where ∆p is measured in pascal.
In many applications, water is assumed to be incompressible.
By reference to the expression, justify this assumption.

Please explain it.

since water is incompressible the change in deltaV/v will be very less as water won't compress when the pressure is increased

 

[Hassi123]

interference
Wave interference is the interaction between waves that meet. Like if there are two waves travel at the opposite direction, they gotta pass through each other. There are 2 types of wave interference : constructive and destructive.

Constructive interference is the interference that occurs when waves combine to make a wave with a larger amplitude (distance from the crest or trough to their rest position). Two waves approach each other. The crest's new amplitude is the sum of the amplitude of the original crests. After meeting the waves continue as if they had not meet.

Destructive interference is when two waves combine to make a wave with a smaller amplitude. It's ALWAYS occur when the crest of one wave overlaps the trough of the other wave. The only with the larger amplitude always takes the shape of the interference. If the original waves had equal amplitude, then the crest and the trough can completely cancel each other out

And unlike superposition Interference does require conditions to be carried out like
1)both waves should be of the same type
2)should meet at a point
3)they should have no phase difference

hmm im confused, i read somewhere that for complete destructive interference there should be a phase difference of 180 degrees :/ this leads to trough over crest

 

[applepie1996]

hey can u explain to me these topics coz i never understand them:
1) phase
2) superposition
3)path difference
4) interference

it will b very greatful if u explain them in detail.........
THANKS

i just did explain them 2 u y don't u check it out

 

[applepie1996]

hmm im confused, i read somewhere that for complete destructive interference there should be a phase difference of 180 degrees :/ this leads to trough over crest

the phase difference should b of evn multiples of 180

 

[Rakayz]

HOPE U GET IT !!!!!

thanks alot!!

 

[applepie1996]

thanks alot!!

ur welcum nd best of luck for ur examz