# Physics: Post your doubts here!

#### XPFMember

XPRS Moderator
Hi everyone, AsSalamoAlaikum Wr Wb...

To get things organized in a better way, I am making this thread. As othewise, some queries remain unanswered!

So post your PHYSICS doubts in this thread. InshaAllah other people here will help me and you all.  Any Physics related notes and links will be added here in this post. Feel free to provide the links to your notes around the forum, or any other websites! Thanks!
Jazak Allah Khair!

Physics Notes:

As physics p1 MCQS YEARLY Solved [explaination]
Physics Practical Tips - by arlery

AS and A-Level Physics Definitions

Physics Compiled Pastpapers: <Credits to CaptainDanger for sharing this..>

Here are the compiled A level topical Physics questions in PDF form...

Paper 2 & Paper 4 : http://www.mediafire.com/?g65j51stacmy33c

(Source : http://www.alevelforum.com/viewtopic.php?f=15&t=14)

#### zain tariq

Re: Physics Help here! Stuck somewhere?? Ask here! in physics may/june 2002 paper 4 question 4 part c
how can we predict a change in the period or amplitude of motion whwn we donot know the SHm equation of the motion...like for spring-mass system we know the equation;T=2pisquare root of m/k...through which can predict the effect on period.........but in this question no such equation is given so how to answer it?????

• aniroula

#### destined007

Re: Physics Help here! Stuck somewhere?? Ask here! In case you haven't noticed, the motion of plank is also simple harmonic.
So period is proportional to mass. mass decreases period decreases.
amplitude increases because pull has decreased.

#### destined007

Re: Physics Help here! Stuck somewhere?? Ask here! mury456 said:
help with this !!

A uniform plank of 60N is 2000 mm long rests on a support that is 600 mm from the end E.

At what distance from E must a 160N weight be placed in order to balance the plank ?

#### dhatri2005

Re: Physics Help here! Stuck somewhere?? Ask here! Problems in june 2011 paper 11

No 25, 27, 29, 32, 35,, 36,37..

And also can u send me some notes on potential divider, internal resistance along with some working examples which cover the whole chapter...

• EngineerEr and MemoryMatrix 21

#### wahab305

Re: Physics Help here! Stuck somewhere?? Ask here! 32- 9v is emf..and emf is energy converted into electrical/charge..so its A
B is wrong because emf is sent to the whole circuit
C is wrong because we dont know circuit is parallel or series because in series emf divides and in parallel same
D is wrong because 9v rating is not potential difference

#### wahab305

Re: Physics Help here! Stuck somewhere?? Ask here! dhatri2005 said:
Problems in june 2011 paper 11

No 25, 27, 29, 32, 35,, 36,37..

And also can u send me some notes on potential divider, internal resistance along with some working examples which cover the whole chapter...
35-simple electricity
total resistance all in parallel so its R=10/17 ohms
total voltage or in short emf= v=ir V=10/17 X 5=2.94V
voltage will be same in parallel so I=V/R R=10/17 V=2.94 I=1.5A

#### wahab305

Re: Physics Help here! Stuck somewhere?? Ask here! dhatri2005 said:
Problems in june 2011 paper 11

No 25, 27, 29, 32, 35,, 36,37..

And also can u send me some notes on potential divider, internal resistance along with some working examples which cover the whole chapter...
36.......simple concept.....if the resitance decreases the current increases..when u remove the resitor...now its in series meaning the whole current flows through it and will have more current in it...Y and Z resistor will be having lesser current because when there was w resistor current was same so answer is C

• khaledkhondker and aniroula

#### wahab305

Re: Physics Help here! Stuck somewhere?? Ask here! dhatri2005 said:
Problems in june 2011 paper 11

No 25, 27, 29, 32, 35,, 36,37..

And also can u send me some notes on potential divider, internal resistance along with some working examples which cover the whole chapter...
37 is a bit tricky question but its really simple indeed .....u can see that lamp is off when resistance of the wire is less than r1 and r2 because current flows through easier path...so we found the point with the least resistance which is not A B C i-e D because this gives the smallest resitance...cheers.... #### a021011

Re: Physics Help here! Stuck somewhere?? Ask here! 9702_s05_qp1 - Q16, 22, 36

Thanks

#### destined007

Re: Physics Help here! Stuck somewhere?? Ask here! a021011 said:
9702_s05_qp1 - Q16, 22, 36

Thanks

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#### Xthegreat

Re: Physics Help here! Stuck somewhere?? Ask here! is this for AS or A2?

if A2 then this is my question. O/N10 paper 43. Q3b

thanks.

#### hateexamz

Need help with A2 Physics

Guyz i need help in the following question frm year 2003 Physics Paper 4 Q1 (c) :%)

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#### destined007

Re: Physics Help here! Stuck somewhere?? Ask here! Xthegreat said:
is this for AS or A2?

if A2 then this is my question. O/N10 paper 43. Q3b

thanks.
1)
d = –4cos(120)= 2 cm

so the piston will be 2 cm above above AB and moving upward.

2)d=-4cos(240)= 2 cm
so the piston will be 2 cm above AB but in this case it has traveled all the way to CD and back towards AB.

• ArOoj Jaleel

#### destined007

Re: Need help with A2 Physics

hateexamz said:
Guyz i need help in the following question frm year 2003 Physics Paper 4 Q1 (c) :%)
i)
change in φ = φ1-φ2= GM/R1-GM/R2= GM(1/R1-1/R2)
= 6.67 x 10^-11 x 6.0 x 10^24 x(1/(6.4 x 10^6)- 1/(6.4 x 10^3 + 1.3 x 10^4))====> solve this

ii)
according to law of conservation of energy:
½mv^2=mφ where mφ= change in potential energy
½v2 = φ as m cancels
now just plug in the value of φ from part 1.

#### mufc102

Re: Physics Help here! Stuck somewhere?? Ask here! Help J04/P1/Q.9,Q.17,Q.18,Q.31
N04/P1/Q5,16,20

#### Abdulrab

Re: Physics Help here! Stuck somewhere?? Ask here! Can anyone tell me what should i learn for pressure in lquids for As level and please give me the detailed explanation of viscosity in liquids asap !!! thanks

#### Abdulrab

Re: Physics Help here! Stuck somewhere?? Ask here! can someone kindly post the notes on momentum by naushad or any other good teacher ??

Thanks!

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