Physics: Post your doubts here!

[krishnapatelzz]

hi does anyone have access to physics past paper of 1997 and its ms?

why do you need to solve that old paper ! from 2002 you can solve, which are available on gceguide .

 

[krishnapatelzz]

9702/w16/51
qtn 2 how to make the error bars
will it be horizontal or vertical as usual....how to do it can anyone plzz show
can someone plzz solve the complete qtn 2

it will be horizontal , it says show error bars for X (it is in x-axis ). for thing like this try to understand rather than remembering things . there is uncertainty in the value of X so we draw error bars to show the maximum or minimum value it can go from the accurate value .

 

[Holmes]

Explain why the answer is D
Thanks in Advance

 

[kungfuPanda]

Hi
Can you guys help me out with paper 3 ,I have a simple question.
What do i have to keep in mind while taking readings from instruments?
Like measuring masses or time ,Is it always good to round off numbers during measurements for final readings at the start of Question 1 or 2 ?

 

[areeba240]

9702_w12_qp_43
qtn 7 b(ii)
can anyone plzz explain me this

 

[krishnapatelzz]

9702_w12_qp_43
qtn 7 b(ii)
can anyone plzz explain me this

if u remember in AS the wave chapter , for a visible fringe to be seen the wavelength of light should be almost equal to the slit space . so here the electron is replaced with light and the crystal acts like a slit as it has space between them , the space(separation of crystal ) is about the size of wavelength so can be used in electron diffraction.

 

[Shuddho Ukil]

Help please?
Need help with question number 2 c (ii) from paper 22 of summer 2012.
I've attached the question.
Would highly appreciate any help. Thanks!

 

[Bishnu Dev]

Help please?
Need help with question number 2 c (ii) from paper 22 of summer 2012.
I've attached the question.
Would highly appreciate any help. Thanks!

The Potential Energy of the ball when it is at A changes to Kinetic Energy as the ball accelerates downwards (It's velocity increases, so KE also increases). After the ball hits the ground, it rebounds upwards with decreasing velocity and increasing height, so KE changes to Potential Energy.

 

[Bishnu Dev]

see solution 120 at
http://physics-ref.blogspot.com/2014/11/physics-9702-doubts-help-page-22.html

It's not clearly explained. Why doesn't the current flow through Q?

 

[Salim Dridi]

Al Salamou alaikom,
What is the number of Decimal Places to put our answer for VOLTAGE to in Paper 3 Practical when we put the Voltmeter/Multimeter to the 20V setting.
P.S. in the multimter, when we put setting to 20V, it gives us a reading with 2 d.p. i.e. 5.36 V so should we put our answer to 1 or 2 or no d.p.

 

[Shuddho Ukil]

The Potential Energy of the ball when it is at A changes to Kinetic Energy as the ball accelerates downwards (It's velocity increases, so KE also increases). After the ball hits the ground, it rebounds upwards with decreasing velocity and increasing height, so KE changes to Potential Energy.

Thanks!

 

[i_try9621]

Al Salamou alaikom,
What is the number of Decimal Places to put our answer for VOLTAGE to in Paper 3 Practical when we put the Voltmeter/Multimeter to the 20V setting.
P.S. in the multimter, when we put setting to 20V, it gives us a reading with 2 d.p. i.e. 5.36 V so should we put our answer to 1 or 2 or no d.p.

better if you use 5.36V

 

[i_try9621]

Someone please help me with 6) iv). It's from 41/O/N/11

 

[Thought blocker]

View attachment 61960 View attachment 61961 Someone please help me with 6) iv). It's from 41/O/N/11

Zero

 

[i_try9621]

Zero

but why?

 

[Thought blocker]

but why?

Mean voltage so.. xD

 

[krishnapatelzz]

Mean voltage so.. xD

 

[Albeit]

Can someone please find the uncertainty in logP when P(20.5+-0.5).Many thanks in advance..

 

[i_try9621]

Can someone please find the uncertainty in logP when P(20.5+-0.5).Many thanks in advance..

Two ways of doing it
log(20.5 + 0.5)-log(20.5) = 0.01
OR
log(20.5)-log(19) = 0.01
both ways can be done

 

[Holmes]

see solution 129 at
http://physics-ref.blogspot.com/2014/11/physics-9702-doubts-help-page-24.html

thank you bro....