Physics P3 (Practical) Notes and Tips

[kitkat <3 :P]

y bee i tagged

aween

 

[Batguy]

aween

 

[papajohn]

View attachment 42869 M sorry about my terrible handwriting

That indeed a valuable piece of information, thanks for sharing

 

[kitkat <3 :P]

That indeed a valuable piece of information, thanks for sharing

no problem

 

[Jassim]

hey i have 2 questions..first when we have like a pendulum question and we have to change d... it always says in the ms that d should be measured to the nearest mm what do they mean and second some sources of error relating to like question where u have to push a ball or an object is that its difficult to release the ball without applying a force and the improvement has something to do with using a electromagnet.. can u explain that plx

You need to be clearer on the first question just a bit more, or direct me to the marking scheme. For your other question, I found the question by pure chance. What it simply means is that because we apply a force on the car as we release it to go down the slope, this extra force by our hand causes it to go further than it should under the force of ONLY its own weig. To improve this, we should use a electromagnet which, when it is activated, holds the car in place at the top of the slope. When we turn it off, the car is no longer held by the electromagenet and moves down the slope under its own weight.

 

[Princess Raven]

You need to be clearer on the first question just a bit more, or direct me to the marking scheme. For your other question, I found the question by pure chance. What it simply means is that because we apply a force on the car as we release it to go down the slope, this extra force by our hand causes it to go further than it should under the force of ONLY its own weig. To improve this, we should use a electromagnet which, when it is activated, holds the car in place at the top of the slope. When we turn it off, the car is no longer held by the electromagenet and moves down the slope under its own weight.

I am so sorry I forgot Which year it was and couldn't find it..OHHH I get the electromagnet thing now thank u so much
And for the distance question it's in every year in the table it says distance should written to the nearest mm it's not
In the question but the marking schemes have it as a mark like for example if we get a reading to be 0.385 m is this written to the nearest mm?

 

[aisha rasheed]

anyone having idea what is going to come in physics 33 ? im also giving it on 20th may

 

[ZaqZainab]

Thought blocker here you go

 

[kalpaveen]

Can Someone Please tell me the important least counts that we should know??

 

[huh]

Hey guys, its my first time doing practical and I got no practice. Is there time allocated for setting up the experiment or is setting up part of the 2 hours.

 

[papajohn]

Hey guys, its my first time doing practical and I got no practice. Is there time allocated for setting up the experiment or is setting up part of the 2 hours.

Dude, dont worry. Do practice the uncertainity

 

[Jassim]

Hey guys, its my first time doing practical and I got no practice. Is there time allocated for setting up the experiment or is setting up part of the 2 hours.

You set it up within the two hours. You are provided with a checklist before it starts to mark if you have everything. If its too difficult to set up (electricity) ask the invigilator to set it up for you. You will LOSE 2 marks for this though.

 

[Jassim]

I compiled a list of error and improvements for the last part of question 2 in physics paper 3. Only the first one you can use everywhere, as long as the question requires taking any type of measurement at all. These are all from the past papers marking schemes. These could be helpful if you're running out of time and had memorized these before, but please make sure these error and improvements fit the question!


1. Error: Two readings not enough to support the conclusion
Improvement: Take more sets of readings and plot a graph.
(This one works everywhere. Memorize this!)

2. Error: Large uncertainty in measured quantity because quantity is too small (like when measuring the thickness of an object)
Improvement: improved method to calculate this quantity like taking more readings at different parts of the object and dividing by number of readings for an average.

3. Error: Friction with surface (apply to any object that you have to pull on a surface)
Improvement: apply lubricant to surface

4. Error: (only when newton meter used horizontally!) Zero error on newton meter when used horizontally.
Improvement: adjust vertical arrangement of newton meter.

5. Error: (Keeping an object at certain height with your hands for a long time) keeping "object" at a certain height difficult
Improvement: use a clamp/tape.
ELECTRICITY:

6. Error: Voltmeter scale not sensitive enough/not precise enough
Improvement: Use a digital voltmeter/use a voltmeter that reads to 0.01 V.

7. Error: Wire not straight/wire kinked (coils) / difficulty in keeping wire straight
Improvement: Tape wire to a ruler/ clamp wire.

8. Error: Contact resistance/fluctuating ammeter or voltmeter readings
Improvement: Sand the crocodile clips to clean them/ tighten clips

OSCILLATIONS

9. Error: Difficult to judge start/center/ end of swing / complete swing
Improvement: use fiducial marks/pointer

10. Error: large uncertainty in time / time taken too short
Improvement: use video and timer that captures frame by frame video

11. Error: Object does not travel in a straight line
Improvement: Method of guiding object to travel in a straight line

-------------------------------------------------------------------------------------------------------------
12: Error: (when measuring degrees in an experiment that's suspended in the air like the degrees between a rubber band when stretched) difficult to hold protractor steady
Improvement: project image of the rubber band onto a screen.

13: Error: applying a force on the object when releasing it
Improvement: use an electromagnet to release the object so it falls/moves on a slope or surface under the force of its own weight.

 

[Jassim]

In the paper, there's a question that says, "explain whether your results support the suggested relationship?" Anyone know how to solve this part?

 

[Mohammed salik]

In the paper, there's a question that says, "explain whether your results support the suggested relationship?" Anyone know how to solve this part?

Use the Formula :-
K=Constant..!
Now use %Diff=K1-K2/K(avg) * 100

If u Percentage Diff. Lies within 10%. i.e <10%. So ur results supports the The suggested relationship!

 

[Mohammed salik]

I compiled a list of error and improvements for the last part of question 2 in physics paper 3. Only the first one you can use everywhere, as long as the question requires taking any type of measurement at all. These are all from the past papers marking schemes. These could be helpful if you're running out of time and had memorized these before, but please make sure these error and improvements fit the question!


1. Error: Two readings not enough to support the conclusion
Improvement: Take more sets of readings and plot a graph.
(This one works everywhere. Memorize this!)

2. Error: Large uncertainty in measured quantity because quantity is too small (like when measuring the thickness of an object)
Improvement: improved method to calculate this quantity like taking more readings at different parts of the object and dividing by number of readings for an average.

3. Error: Friction with surface (apply to any object that you have to pull on a surface)
Improvement: apply lubricant to surface

4. Error: (only when newton meter used horizontally!) Zero error on newton meter when used horizontally.
Improvement: adjust vertical arrangement of newton meter.

5. Error: (Keeping an object at certain height with your hands for a long time) keeping "object" at a certain height difficult
Improvement: use a clamp/tape.
ELECTRICITY:

6. Error: Voltmeter scale not sensitive enough/not precise enough
Improvement: Use a digital voltmeter/use a voltmeter that reads to 0.01 V.

7. Error: Wire not straight/wire kinked (coils) / difficulty in keeping wire straight
Improvement: Tape wire to a ruler/ clamp wire.

8. Error: Contact resistance/fluctuating ammeter or voltmeter readings
Improvement: Sand the crocodile clips to clean them/ tighten clips

OSCILLATIONS

9. Error: Difficult to judge start/center/ end of swing / complete swing
Improvement: use fiducial marks/pointer

10. Error: large uncertainty in time / time taken too short
Improvement: use video and timer that captures frame by frame video

11. Error: Object does not travel in a straight line
Improvement: Method of guiding object to travel in a straight line

-------------------------------------------------------------------------------------------------------------
12: Error: (when measuring degrees in an experiment that's suspended in the air like the degrees between a rubber band when stretched) difficult to hold protractor steady
Improvement: project image of the rubber band onto a screen.

13: Error: applying a force on the object when releasing it
Improvement: use an electromagnet to release the object so it falls/moves on a slope or surface under the force of its own weight.

Thnx Man..!!

mehria

 

[Autumngirl]

When drawing a line of best fit, is it necessary for it to pass through points? What if you're getting a perfect line that doesn't pass through any points but has points balanced on its sides very close to it? Also, does taking 1 large box as 0.25 units qualify as awkward scale or not?

 

[Jassim]

When drawing a line of best fit, is it necessary for it to pass through points? What if you're getting a perfect line that doesn't pass through any points but has points balanced on its sides very close to it? Also, does taking 1 large box as 0.25 units qualify as awkward scale or not?

When you draw a line of best fit, you must have two points on the line. The other should be close to either sides of the line, not necessarily on the line, just a equal number of points above and below. Mark the points with a X, and if there is any value that's an anomaly, then plot it, and circle it so you can show the examiner that you know its a awkward value. My advice: plot for the graph. That's means when you plot, change and mark points closer to the line. Then alter these coordinates in your table. This gets you an accuracy mark, if you weren't getting it already.
As for the scale, a scale is acceptable as long as you aren't taking divisions of three (3, 6, 9) or any division that you are required to input into your calculator to find how much to space it out. The scale you have suggested MAY be correct, depending on the question. Why don't you check the marking scheme of the specific question?

 

[Autumngirl]

When you draw a line of best fit, you must have two points on the line. The other should be close to either sides of the line, not necessarily on the line, just a equal number of points above and below. Mark the points with a X, and if there is any value that's an anomaly, then plot it, and circle it so you can show the examiner that you know its a awkward value. My advice: plot for the graph. That's means when you plot, change and mark points closer to the line. Then alter these coordinates in your table. This gets you an accuracy mark, if you weren't getting it already.
As for the scale, a scale is acceptable as long as you aren't taking divisions of three (3, 6, 9) or any division that you are required to input into your calculator to find how much to space it out. The scale you have suggested MAY be correct, depending on the question. Why don't you check the marking scheme of the specific question?

My scale requires a bit of calculation, 1 small box is 0.04 units so counting without calculation is kind of risky. As for the mark schemes, all the recent ones give only one example of (3,10) as an awkward scale and that's it. My teachers in school marked my scale right but I have a niggling feeling that they don't adhere strictly to the mark schemes when they grade our work.
Anyway, thank you for help,it's hard to get such comprehensive replies!

 

[hellblender]

Do you guys draw curves with flexi curve ruler or with a free hand?