PHYSICS ATP TIPS, EXPERIMENTS AND FEQs

[maham baqir]

I will try to put everything i have learned from doing past papers into nutshell.

Frequently examined question:​

• theory suggests that resistance should be 10 ohm but in experiment value is 12. Given that experiment had no errors, does this experiment support theory?Experiment supports theory as the result is very close to theoretical value. it is not exact due to resistance of wire changes with time and the resistance of amm meter is not counted.
• Student has decided to repeat this experiment what she needs to keep constant?
  (u can write any variable that affects the results such as) the volume of water in container, room temperature, the distance of string from centre.
• Bottom of the object is not visible on the screen, how to adjust it?
  object, image and lens should be in line(their horizontal axis must be same)
• The image is not sharp(blurred), WHY is not sharp and HOW can u sharp this image?
  It is not sharp as light from object does not meet at single point. u can correct it by adjusting screen/lens so that the screen is exactly at the focal distance of lens.
• Why angle of incidence is not same as angle of reflection?
  The lines were too thick. normal was not drawn accurately. parallax error
• How to accurately measure the thickness of coins?
  place atleast 10 coins. take their thickness. divide by 10. OR use micrometer screw guage.
• Why it is not possible to take length XY with a single ruler?
  because the blank space will affect accuracy of result therefore second ruler is needed to measure the blank-space and subtract it from final answer.
• Why it is important for the rule to be very close to XY.
  to take accurate reading by avoiding parallax error.
• How to avoid parallax error?
  By keeping line of sight perpendicular to the scale.
• Why ammeter has been deflected to -2 written on other side of the zero?
  wrong connection of terminals/positive wire connected with negative wire.
• Why there are two negative terminals on a volt meter marked 3V and 10 V?When connected to 3V the range will be 0-3V and when connected to 10V the range will be 0-10V. it is useful for measuring accurately more ranges of voltages.
• The current is approximately 3 A. which range should student use, 0-10A or 0-5A.
  the smallest range that can accommodate the required current. therefore 0-5A
• How to measure the volume of irregular shaped object?
  By putting fixed volume of liquid in measuring cylinder and taking the initial reading. then add object and take final reading. then subtract initial from final.
• Why is resistance of R set to maximum before closing switch?
  so that current is lowest on start and increased in decreasing resistance as more in needed. to avoid equipments from malfunctioning.
• How to make sure the results are accurate?
  1-the N oscilations and then divide the Tn By N to get T
  2-Take many readings and average them.
  3-Take reading for different values of I then plot I against V. draw a best fit and then find V/I(resistance)
• Why the reading is taken for 20 oscillations?
  to reduce human error in reading time. as average will be less affected as proportion of delay will be less in 20 oscilations.

I will add more as i remember. i will add experiments and important tips as well..​

these are good.

 

[maham baqir]

This is all I have for tomorrow.
I'm not particularly very good at this ATP so the tips/notes are not like yesterday.
robinhoodmustafa.

thanks

 

[aathil]

Thanks guys!..you guys really do soo much!

 

[Suchal Riaz]

Saad Mughal do you remember when atp used to be difficult for us. now we actually do the practical and it is full of mini-heart-attacks

 

[Saad Mughal]

Saad Mughal do you remember when atp used to be difficult for us. now we actually do the practical and it is full of mini-heart-attacks

Haha, yes. ATP seems much easier and simpler now.

 

[Suchal Riaz]

Haha, yes. ATP seems much easier and simpler now.

electricity practicals are designed by the devil himself. weird things happen. i increase the resistance and the current is increasing. when i noticed it i repeated the experiment but the same result.

 

[Saad Mughal]

electricity practicals are designed by the devil himself. weird things happen. i increase the resistance and the current is increasing. when i noticed it i repeated the experiment but the same result.

Faulty instruments, low precision, various errors, faulty experimental techniques. We only WROTE this in ATP exams, now we experience it.

 

[Dubi Pro]

Experiment post has been updated. https://www.xtremepapers.com/commun...-tips-experiments-and-feqs.25526/#post-520817

Bro! please tell me what how and why this means. i tried a simple method a ruler to measure a line in atp, i got in cm obviously but the mark scheme said some another answer that too in mm

is it something to do with this tip?

• Why it is not possible to take length XY with a single ruler?
  because the blank space will affect accuracy of result therefore second ruler is needed to measure the blank-space and subtract it from final answer.

 

[Dubi Pro]

Faulty instruments, low precision, various errors, faulty experimental techniques. We only WROTE this in ATP exams, now we experience it.

Bro! please tell me what how and why this means. i tried a simple method a ruler to measure a line in atp, i got in cm obviously but the mark scheme said some another answer that too in mm

is it something to do with this tip?

• Why it is not possible to take length XY with a single ruler?
  because the blank space will affect accuracy of result therefore second ruler is needed to measure the blank-space and subtract it from final answer.

 

[Suchal Riaz]

Bro! please tell me what how and why this means. i tried a simple method a ruler to measure a line in atp, i got in cm obviously but the mark scheme said some another answer that too in mm

is it something to do with this tip?

• Why it is not possible to take length XY with a single ruler?
  because the blank space will affect accuracy of result therefore second ruler is needed to measure the blank-space and subtract it from final answer.

For measuring a line a single ruler is enough. But if u are taking height from ground the blank space will affect your reading so u must see what is length of the blank space and then add it to the height.
In your case, the answer would be acceptable in cm, mm or ?provided that examiner didn't the specify the unit already.

 

[Dubi Pro]

For measuring a line a single ruler is enough. But if u are taking height from ground the blank space will affect your reading so u must see what is length of the blank space and then add it to the height.
In your case, the answer would be acceptable in cm, mm or ?provided that examiner didn't the specify the unit already.

what is this blank space? even if i measured from ground :S im hearing this first time never done it! :S

any help?

 

[Suchal Riaz]

what is this blank space? even if i measured from ground :S im hearing this first time never done it! :S

any help?

If u don't imagine the things you have not seen how would you do atp. I never saw it. It came into my mind automatically when i saw an atp paper with reference to this.
Here is the image to help you understand it.
https://www.dropbox.com/s/eewxlfrqb43pm4r/Untitled Notebook - 20131020_135601 - 2.png
This link would be deleted after few days so download it asap.

 

[Dubi Pro]

If u don't imagine the things you have not seen how would you do atp. I never saw it. It came into my mind automatically when i saw an atp paper with reference to this.
Here is the image to help you understand it.
https://www.dropbox.com/s/eewxlfrqb43pm4r/Untitled Notebook - 20131020_135601 - 2.png
This link would be deleted after few days so download it asap.

thanks alot. i had confusion just because of 1 paper which is

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s08_qp_6.pdf

Q4, b ii the measurement part.

what happened is i measured normally with cm i got 0.8 cm.

but in markscheme its like 13 that too mm!

i dont knw if we write in mm or cm.

 

[Suchal Riaz]

thanks alot. i had confusion just because of 1 paper which is

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s08_qp_6.pdf

Q4, b ii the measurement part.

what happened is i measured normally with cm i got 0.8 cm.

but in markscheme its like 13 that too mm!

i dont knw if we write in mm or cm.

When you print the paper, you legal size sheet and disable stretching or 'fit to the size' or any equivalent option so the original dimension are conserved.

 

[annievalentina]

Thank you for useful atp notes