physics p5 discussion

[WellWIshER]

guys how to deal with ans in standard form can someone tell me their q2 part d in june 08????

 

[samy]

hey...for who ever sayx that log cant b used for finding uncertainities...
WELLL..it CAN be used...did couple of papers using it.....getting exact MS answers..

so heres the waylike V is given 3.6+-0.2 and v have to find ln V along with uncertainity...
well ln V woukd b 1.28 and for uncertainity do (ln(3.4) - ln(3.8 )) / 2...
note WHOLE of it is divided by 2...
u can chek get any paper asking to find error in ln values this would definitely work...
but remember itx only used where it asks to find value for ln...like ln V!!!

 

[samy]

guys how to deal with ans in standard form can someone tell me their q2 part d in june 08????

dude i would be done with the papers by tomorow morning (maybe lol)
so i will tell u about this den if nobody wud have answered u by then ..

 

[samy]

can anybody please clear my concept about drawing of error bars...
like i have error of 0.06 so i have to draw 0.06 length line according to my axiz above the point and same length below the point as well rite??

 

[maihunpagal23]

how to calculate errors in the Y intercept if we have errors in the gradient.. I am taking reference to nov 07 ques 2 where I correctly calculated the uncertainties in the gradient but how to find uncertainty in the Y intercept using Y=mx+c??

 

[fluffycloud]

You find Y intercept of best fit line and worst acceptable line,and subtract the two.

My doubt- In oct/Nov 2009 Paper 51 Its a negative gradient right?
So how to find the y intercept.
I don't get how to find y intercept......!

 

[srukhan]

okay my best fit line was flawless so far till i reached Nov 2009(52) and the points just refuse to lie in a straight line, HELP!
and guys do upload a few graphs of yours so we get to understand better, the error bars and stuff
Posting my doubts again, In hope that someone would reply
-Nov 2009/Q2 My besf fit line(joining the 4 dots that fall perfectly in line) does not pass through the points mentioned in the mark scheme?
-also, June 10 variant 1/Q2 uncertainity in Xc?
-variant 2/Q2 part e

 

[srukhan]

You find Y intercept of best fit line and worst acceptable line,and subtract the two.

My doubt- In oct/Nov 2009 Paper 51 Its a negative gradient right?
So how to find the y intercept.
I don't get how to find y intercept......!

he's right, about finding the y intercept..
and as for Nov/2009: I did it this way lgG=hlgT-lgR
so, lgG=(-4.2)(2.496)-2.88
lgG=-13.4

Bring it on peeps, how did guys you do it?

 

[fluffycloud]

Btw 'She's' right! Tis cool

So the points y and x while finding 'c' (y=mx+c) can be any corresponding points?

 

[workinghard]

@magicmanfarhanul.....
plx donot ruin da concepts!
i nw u meant well .. but u r unfortunately wrong
we change da independent variable that is value on x axis n it changes the dependent variable dat is on yaxis
n dependent variable is NOT dependent on US it is dependent on the idependent variable....
like in LDR design v change the length dat is independent nd resistance changes as a result dat is dependent ON legth!!!!
u chk ms if not agree wid me...
n errors r also calc da wy i told
i promise i tld da rite way plx show some trust here
its in da cambridge endorsed books as well
hope u dont mind my disagreein wid u
i jst dont want ppl 2 lose marx!!!
@srukhan thnx 4 liking my signature n i askd in which grafs r da bars horizontal ???
n i m sorry i missed ur ques which graf is troubling u?!

 

[nisurju]

You find Y intercept of best fit line and worst acceptable line,and subtract the two.

My doubt- In oct/Nov 2009 Paper 51 Its a negative gradient right?
So how to find the y intercept.
I don't get how to find y intercept......!

he's right, about finding the y intercept..
and as for Nov/2009: I did it this way lgG=hlgT-lgR
so, lgG=(-4.2)(2.496)-2.88
lgG=-13.4

Bring it on peeps, how did guys you do it?

use y=mx +c and put gradient negative and u can use any point for x and y.so u can find c!

 

[intel1993]

hey can anaone tell that where signal generator is used specifially?

 

[zeebujha]

hey can anaone tell that where signal generator is used specifially?

Signal generator is used whenever an electrical signal of particular frequency and amplitude is required in the experiment. This SIGNAL is used to control various apparatus
For eg:
When you are using a loudspeaker, which usually converts an electrical audio signal to a sound wave, you need a signal generator
When you are using a vibrator,to vibrate a string under tension, you would need to plug it into a signal generator. The signal generator would determine the frequency at which the vibrator vibrates and the amplitude of its vibration

So, we can say that the signal generator doesn't have any "specific" use

 

[intel1993]

hey can anaone tell that where signal generator is used specifially?

Signal generator is used whenever an electrical signal of particular frequency and amplitude is required in the experiment. This SIGNAL is used to control various apparatus
For eg:
When you are using a loudspeaker, which usually converts an electrical audio signal to a sound wave, you need a signal generator
When you are using a vibrator,to vibrate a string under tension, you would need to plug it into a signal generator. The signal generator would determine the frequency at which the vibrator vibrates and the amplitude of its vibration

So, we can say that the signal generator doesn't have any "specific" use

thnx...........can u tell me one more thing that why in oct/nov 2010 p52 q1 we cant use the one circuit in whole for coil x and coil Y whats the point of two indivisual circuits em bit confused in dat.................?????

 

[zeebujha]

hey can anaone tell that where signal generator is used specifially?

Signal generator is used whenever an electrical signal of particular frequency and amplitude is required in the experiment. This SIGNAL is used to control various apparatus
For eg:
When you are using a loudspeaker, which usually converts an electrical audio signal to a sound wave, you need a signal generator
When you are using a vibrator,to vibrate a string under tension, you would need to plug it into a signal generator. The signal generator would determine the frequency at which the vibrator vibrates and the amplitude of its vibration

So, we can say that the signal generator doesn't have any "specific" use

thnx...........can u tell me one more thing that why in oct/nov 2010 p52 q1 we cant use the one circuit in whole for coil x and coil Y whats the point of two indivisual circuits em bit confused in dat.................?????

As far as I remember, we need to know the effect of change in B (due to the AC in coil X) on the magnitude of emf induced in coil Y. So, coil X is supposed to have a power source connected to it as a source of AC(which could be the signal generator). But coil Y cannot have power source connected to it as the emf induced has to due to the change in B , not due to an external power source. Thus, X and Y have to be a part of different circuits

 

[intel1993]

ohh thnx get it...

 

[maihunpagal23]

for the triangles which are to be drawn in finding the gradient, do we need to draw two triangles? One for the best fit line and other for the worst fot line?? Please explain this.

And one thing more, how many significant figures do we need to include in our table?

 

[samy]

can anybody please clear my concept about drawing of error bars...
like i have error of 0.06 so i have to draw 0.06 length line according to my axiz above the point and same length below the point as well rite??

what?? nobodyx gona reply me??

 

[beacon_of_light]

It's better if you draw a triangle for the best fit line but that's not necessary for worst fit line, although drawing a triangle there might help the examiner in locating your points...
well @significant figures, look at the axis on the graph paper and see whether the x-axis/y-axis allow for 2 or 3 significant figures...and then calculate your values in the table...

 

[beacon_of_light]

can anybody please clear my concept about drawing of error bars...
like i have error of 0.06 so i have to draw 0.06 length line according to my axiz above the point and same length below the point as well rite??

what?? nobodyx gona reply me??

yeah yeah that's the correct way ...