Physics p33 errors

[sse2010]

hey guyz...i've heard that the 2 qs that r cumin wud be of oil viscosity n a diode exp. i wantd to ask one thing..yar in practicalz there is one qs abt graph n the other in which u hav to tell abt 4 errors n how to improve those errors...do u hav any idea wat the errors n their improvemnts can be for both oil viscosity n diode exp...cuz itz nt clear yet dat wich qs wud be of graph n which one wud be for the 4 erorrs!
plz share ur opinions so dat we can benefit frm each other.

 

[Anomaly]

The one involving the Viscosity would most likely include errors, theyre the usual like:
Inaccurate measurement of say time, (due to human reaction error) remedied by using Light Gates etc.
Or something like 2 readings arent enough (depends on the question), plot a graph with multiple readings

 

[sse2010]

hmm. so u givin p33? hwz ur prep?

 

[angel92]

The one involving the Viscosity would most likely include errors, theyre the usual like:
Inaccurate measurement of say time, (due to human reaction error) remedied by using Light Gates etc.
Or something like 2 readings arent enough (depends on the question), plot a graph with multiple readings

what are light gates??

 

[mzzzz]

u just name light gates
dont worry abt the details
anyway, they r used to start/stop the timer wen ball passes through light beam

 

[mz23]

and what if the diode part is question 2? what could the errors be then? and any more ideas about the errors for viscosity? could it be that the oil that sticks to the ball bearing might affect the rest of the experiment?

 

[wadha]

heyy do u guyzz have idea abt p31
can u plzzz let me knw abt da questions
in detail expect that it is pendulum & electricity????????????????????????????/
plzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

 

[Ab.R0xi0uS]

and what if the diode part is question 2? what could the errors be then? and any more ideas about the errors for viscosity? could it be that the oil that sticks to the ball bearing might affect the rest of the experiment?

i dont think oil sticking is the (correct) error to mention .. instead write there might be error in terminal velocity calculated ..
so use a larger distant cylinder to minimize error

 

[princesszahra]

mention abt take more than 2 readings
and improve it by taking more and plotting a graph!!lol!

 

[rethna30]

I've googled for many sample experiments for this "oil viscocity". And visited a lot of pages to see how the experiment can be done, what are the possible errors, and improvement methods..

These are some of the good answers that I found.

Oil Viscosity

Error

1. small air bubbles are formed on the marble/spheres/(any balls being used) which hindered the motion of the ball
2. two sets of reading not enough to draw a valid conclusion
3. human error in timing
4. marble may have not reached terminal velocity


Method of improvements

1. release the ball/marble just a few mm above the oil surface
2. take more readings and plot a graph
3. use light gate to trigger stopwatch/high speed camera with known time intervals/use video camera with slow motion replay
4. ensure the terminal velocity by increasing the release height/using long tube/measure velocity at two intervals to check terminal velocity reached.

I took three of the errors and method of improvement from october/november 2007 paper 32 question 2 marking scheme.
It is also about terminal velocity.

There are other general improvements that I've found in net...But, I dunno how to state a possible error for them.

1. marble released gently into the top of the solution and that it doesn't touch the side of the tube. Using a wider tube
2. Allow oil to stand for a while to let it settle removing all air bubbles

Another source..
http://www.iop.org/activity/education/P ... e_3683.doc

 

[samir]

@rethna30- Great Work dude....U got anything on question regarding Diode?? I am also trying to search for that... also try and upload it here..thanks...

 

[MAVtKnmJ]

If you are still confused, the oil viscosity one will be the short question and the diode one will be the longer one.
For errors and improvements just go through some of the past papers and marking schemes and figure out which ones are relevant to your experiment

 

[samir]

My doubt is what kind of question can come related to diode.... :?: :?:

 

[maximum_user]

@rethna30...

for other general improvements..errors culd be...
1. time taken to travel a set distance is longer as ball falls through the narrow tube*
2. airbubbles might change the viscosity of oil...

any corrections are accepted!!!

 

[maximum_user]

2.Air bubbles formed in the oil...

 

[maximum_user]

@MAVTKmnJ (took time to copy ur name..lol)

are you pretty sure that Q1 is related to LED..and Q2 to terminal velocity and oil viscosity.....or is it the other way round!!!!!!!!!!!

 

[rethna30]

If you are still confused, the oil viscosity one will be the short question and the diode one will be the longer one.
For errors and improvements just go through some of the past papers and marking schemes and figure out which ones are relevant to your experiment

I'm thinking similar too....

I've went through the past years and electricity questions cam first....followed by questions related to mechanics...

 

[maximum_user]

another error culd be....

>difficulty in judging two marks made on tube
>use rubber bands to make two marks

 

[maximum_user]

difficulty in taking ball bearing out oof the tube
retrieve the ball bearing using a magnet


And to the airbubbles forming on sphere....an improvement could be to keep the ball bearings in the same oil before use to reduce any likelihood of bubbles forming...

 

[maximum_user]

hey rethna du have any tips for q1...as u say it might be concerning electricity...