physics p5 discussion

[samy]

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?

well it depends on youbut ..eventually it is gud to draw two triangles...this is because for finding the uncertainity in gradient u have to subtratct the gradient of worst fit line with the gradient of best fit line. and hence TWO triangles are drawn one for best fit and the other for worst fit!

 

[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??

yeah yeah that's the correct way ...

ok thanx finally sombody anwered it..lol anyway thanku!

 

[maihunpagal23]

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...

i dont get your point regarding significant fig

 

[samsung156]

I am having some problems with the questions in MAY / JUNE - 2010 - Variant 2

Question No 1 - What in the world is a Hall probe? Did anyone write the answer for this question? If so , can you please guide me in the right direction.

This problem is in May / June - 2010 - Variant 1

Question No 2 - How do you calculate the error for Reactance?

 

[sksuriza]

in planning question...do we have to plot an expected graph aswell...or only give the labels for the axisz ...plz urgent!!!

 

[SpiritualGlory]

I am having problems with the the Hal probe too in MAY / JUNE - 2010 - Variant 2

Can someone please explain it out..!

 

[sksuriza]

plane shd be perpendicular....
write (hall probe with teslameter of suitable range)
note the reading of magnetic flux density from testameter.....

 

[sksuriza]

Hall Probe is a device to measure magnetic field strength.
It has a power source and a voltmeter connected to it. Power source is required to make current flow through the device. The slice of the semiconductor has to be perpendicular to the magnetic field lines so that the current is flowing in the direction perpendicular to the lines and thus we get maximum deflection of charged particles.
Similarly, a voltmeter is connected to measure the potential difference across two faces of the semi-conductor (Hall voltage).
The syllabus asks us to know how to use a "calibrated" hall probe.
We can calibrate a hall probe using helmholtz coils. The hall probe can be placed perpendicular to the field lines between the two coils and preferably at the mid-point of the distance between the coils. We can use a formula to calculate the B at the mid-point. So, the corresponding voltage of the hall probe in fact is equal to that value of B. We can vary the value of B by varying the current through the coils and thus we get different values of V for corresponding value of B. The, draw a calibration curve of V against B. And when placed in a field of unknown field strength, check the V and find the required value on X-axis for the value of V on y-axis, which would be the value of B.

 

[sksuriza]

http://www.phys.ufl.edu/demo/5_Electric ... Probe.html

i found ths frm d other forum =P

 

[workinghard]

u dont need 2 draw a graf
can but no need!!!

 

[sksuriza]

u get 2 extra markz...jxt becuz of breaking equation n giving a rough sketch of graph

 

[intel1993]

hey can we draw the worst fit line wth the pen becauuse if we draw both lines with pencil it looks like a mess and if we use dotted lines for the worst fit line it becum difficulot for us to find its gradien so wat shud be done....

N to how much sognificant the answers of gradient shud be given????

 

[sksuriza]

3 sig figure is best...

n no its written on the top instruction page to draw graph with pencil...my teacher says to draw with pencil then label both....

or a better method..
draw best fit n find its gradient
thn draw worst n then its gradient...


tht wd be less confusing

 

[WellWIshER]

CAN SOMEONE TELL ME THEIR ANS 4 Q2 JUNE O8!!

I AM GETTING IN STANDARD FORM!!

 

[sksuriza]

which part?

 

[intel1993]

k thanx...

 

[WellWIshER]

which part?

DA gradient and other parts...

i wanna compare my ans

 

[zeena123]

How to find the error when finding the y-intercept? (For example, Oct/Nov 2007. Question 2- iv.)

 

[workinghard]

@zeena123
find the diff b/w y-intecept of best fit n worst fit line dats ur error!

 

[zeena123]

Thank you