Physics: Post your doubts here!

[_Ahmad]

can someone help me out?
http://maxpapers.com/wp-content/uploads/2012/11/9702_s14_ms_42.pdf ( question 10 biii)


http://onlineexamhelp.com/wp-content/uploads/2014/02/9702_w13_ms_43.pdf ( question 9 biii)


http://maxpapers.com/wp-content/uploads/2012/11/9702_s13_ms_42.pdf ( question 9b)


http://maxpapers.com/wp-content/uploads/2012/11/9702_w12_ms_43.pdf (question 9cii and 9dii)

For the first one

Vin = Votage at the non inverting input - voltage at the inverting input

gain=Vout/Vin

open loop gain is usually very large almost around (x 10^5) if not not specified
Votage at the non inverting input is constant at 1.0V (given) and the voltage at the inverting input is varying.

for the first few seconds voltage at the inverting input is more than that at non inverting input, therefore Vin is neagtive.
Vout will be a large neagtive number which is greater than the supply voltage hence op-amp will undergo negative saturation giving max Vout -5v and therfore diode which is reverse biased (R) will emit light
vice versa

 

[hammadullah]

Hello everyone,

Here are Physics Notes for A Level (A2) chapter wise.

Syllabus Code: 9702

Along with these notes you would also need to refer to the Physics A level Cambridge book for the last three chapters that are:

1. Direct Sensing
2. Medical Imaging
3. Communication Systems

Hope that these notes are helpful

The link for the Notes is given below

Link: http://cieoandalevelnotes.blogspot.com/2015/04/physics-cambridge-level-2-notes-9702.html?m=1

Thank You

 

[eliyeap]

Hi guys, I need help for question 5 (b) iii. Cant quite wrap my head around the answer. Any help is much appreciated. Oh, if its possible, please explain in detail. Thanks.
http://www.acethem.com/pastpapers/a...uestion-paper-2013-summer-paper-2-15506.html/

 

[eliyeap]

Question asks about Apparent weight loss but mark scheme talks about pressure differences between liquids.. Does the contents relate each other? If then, How? View attachment 52345 View attachment 52346

The question is mainly talking about Archimedes Principle. In order for an object to float in water when it is partially submerged, the pressure that is acting upwards from the bottom of the object needs to be equal or more then the weight of the object that is acting downwards. The difference in pressure between this 2 forces gives rise to the buoyant force.

 

[ashcull14]

just want a sketch of the ball when it rebounds horizontally as referred in markscheme

 

[The Sarcastic Retard]

View attachment 52374 View attachment 52375
just want a sketch of the ball when it rebounds horizontally as referred in markscheme

It should be like this.

 

[ashcull14]

u removed ure post??? @sarcastic retard
anyways i knw tht tooo i ws asking about the 'rebound' part as stated in markscheme

 

[The Sarcastic Retard]

u removed ure post??? @sarcastic retard
anyways i knw tht tooo i ws asking about the 'rebound' part as stated in markscheme
View attachment 52379

I misread the question. Sorry for that, the answer was wrong hence I uploaded new. Which makes more sense.

 

[ashcull14]

It should be like this.

ty

 

[The Sarcastic Retard]

ty

Mention not ^-^

 

[eliyeap]

Thank You!

check at
http://physics-ref.blogspot.com/2014/06/9702-june-2013-paper-22-worked.html

 

[ashcull14]

 

[The Sarcastic Retard]

View attachment 52386

you have to shade the area that is between two lines.
Area can be caculated via counting the squares.

 

[princess Anu]

pleasee

 

[ashcull14]

 

[ashcull14]

pleasee



View attachment 52394

is it Acos 30??.....and 90 degree??

 

[Ahmed Aqdam]

View attachment 52397

1. For the dark fringe amplitude for first wave will be maximum and second will be minimum and so the phase difference is 180°.
2. For the bright fringe amplitude for both waves will be maximum.
At the bright fringe total amplitude will be 3.4 units and at dark fringe it will be 0.6 units. Intensity is proportional to square of velocity so ratio is 3.4^2/0.6^2=32

 

[princess Anu]

is it Acos 30??.....and 90 degree??

yeah A cos 30
Can u explain how

 

[ashcull14]

1. For the dark fringe amplitude for first wave will be maximum and second will be minimum and so the phase difference is 180°.
2. For the bright fringe amplitude for both waves will be maximum.
At the bright fringe total amplitude will be 3.4 units and at dark fringe it will be 0.6 units. Intensity is proportional to square of velocity so ratio is 3.4^2/0.6^2=32

got it ty

 

[ashcull14]

yeah A cos 30
Can u explain how