• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Physics: Post your doubts here!

Messages
2,332
Reaction score
9,506
Points
523
in the practical how do you find percentage uncertainty in angles and everything also how do you find gradient and y-intercept from the graphs,

Percentage uncertainity = delta theta/theta x 100
depends on what typs of graph u r talking about.
 
Messages
2,332
Reaction score
9,506
Points
523
can u explain this question 5 b(ii) why we cant use the formula I2R or V2/R why ONLY P=IV ???
and also part c ??
(n)

I^2R and V^2R are only for the external resistance. It can be used to find the power of R in this circuit.
whereas they are asked to find out the power for the internal resistance of the battery.
 
Messages
2,332
Reaction score
9,506
Points
523
can u explain this question 5 b(ii) why we cant use the formula I2R or V2/R why ONLY P=IV ???
and also part c ??
(n)

part c. see bii first. they have asked to calculate the power transformed to cell B. that is it is the power is supplied. It is the power input. the power we got it as 60W. then they have asked to find the energy loss per second. we got it as 22.5. this is lesser than the power supplied to cell B. so if the energy lost is less. it is claer that energy can be stored (in cell A)
 
Messages
115
Reaction score
56
Points
38
part c. see bii first. they have asked to calculate the power transformed to cell B. that is it is the power is supplied. It is the power input. the power we got it as 60W. then they have asked to find the energy loss per second. we got it as 22.5. this is lesser than the power supplied to cell B. so if the energy lost is less. it is claer that energy can be stored (in cell A)

thanks GOD bless u !!!!!
(y)
 
Messages
115
Reaction score
56
Points
38
part c. see bii first. they have asked to calculate the power transformed to cell B. that is it is the power is supplied. It is the power input. the power we got it as 60W. then they have asked to find the energy loss per second. we got it as 22.5. this is lesser than the power supplied to cell B. so if the energy lost is less. it is claer that energy can be stored (in cell A)

can u explain me this question part b(i) and part c
 

Attachments

  • 1.JPG
    1.JPG
    75.8 KB · Views: 12
  • 2.JPG
    2.JPG
    40.2 KB · Views: 13
  • 3.JPG
    3.JPG
    34.1 KB · Views: 6
Messages
121
Reaction score
40
Points
38
If I do Full A-Level physics, will my AS Level grade be eliminated and replaced with the Full A-Level one?
 
Messages
2,332
Reaction score
9,506
Points
523
can u explain me this question part b(i) and part c

bi) they have asked to find the resistance between the points A and B.
Look at the loop only for these 2 points. Its a potential divider circuit. Hence u use the potential divider equations
V(out)= R1/(R1+R2) x V(in)
i.e.
V(out) = R(ab)/(Rab+R(i.e. 1.2 ohms) x V(in)
Subtitute the values and find the answer.
 
Messages
2,332
Reaction score
9,506
Points
523
can u explain me this question part b(i) and part c

As for part c. they have told that the volmeter can be calibrated for readings upto 10 Volts. Isnt this a very small scale?? I mean how much can u calibrate if its for 50 readings... Its a very small scale. we cant be able to do that. However if it would be till 50V. it was possible. The other point would be that if the scale is small. it is clear that the divisions will be non- linear. Ther will be mistakes in calibration so the divisions will not be accurate therfore chances of random errors and hence getting wrong answers.
 
Messages
115
Reaction score
56
Points
38
As for part c. they have told that the volmeter can be calibrated for readings upto 10 Volts. Isnt this a very small scale?? I mean how much can u calibrate if its for 50 readings... Its a very small scale. we cant be able to do that. However if it would be till 50V. it was possible. The other point would be that if the scale is small. it is clear that the divisions will be non- linear. Ther will be mistakes in calibration so the divisions will not be accurate therfore chances of random errors and hence getting wrong answers.

thanks a lot you rocked :p
!!!!!!
 
Messages
115
Reaction score
56
Points
38
As for part c. they have told that the volmeter can be calibrated for readings upto 10 Volts. Isnt this a very small scale?? I mean how much can u calibrate if its for 50 readings... Its a very small scale. we cant be able to do that. However if it would be till 50V. it was possible. The other point would be that if the scale is small. it is clear that the divisions will be non- linear. Ther will be mistakes in calibration so the divisions will not be accurate therfore chances of random errors and hence getting wrong answers.

in marking scheme they did in this way
4/5 x 1200.
how they did it ???
 
Messages
2,332
Reaction score
9,506
Points
523

Then I advise u NOT to look at the mark scheme. First.
Secondly there are different methods of doing the same questions. U try it urself first. if u have a doubt ask someone. And then if u still have a doubt look at the mark scheme. They only give u direct answers. They dont write each and every step.
Thats what my teachers advise me to do.
 
Messages
49
Reaction score
535
Points
93
Can anybody help me find out some of the more difficult questions of Heat, Thermodynamics, Simple Harmonic motion, Gravitation and Centripetal force Chapters? Like if there is any book that contains more difficult questions like there used to be the Abbott in O levels or simply from past papers?
 
Messages
34
Reaction score
7
Points
18
Can somebody PLEASE help with October November 2011 Paper 23 Question 1 D. Sorry couldnt post the link because the website is apparently offline?
 
Messages
115
Reaction score
56
Points
38
Then I advise u NOT to look at the mark scheme. First.
Secondly there are different methods of doing the same questions. U try it urself first. if u have a doubt ask someone. And then if u still have a doubt look at the mark scheme. They only give u direct answers. They dont write each and every step.
Thats what my teachers advise me to do.

why this xtremepapers not opening papers link ???
 
Messages
115
Reaction score
56
Points
38
Then I advise u NOT to look at the mark scheme. First.
Secondly there are different methods of doing the same questions. U try it urself first. if u have a doubt ask someone. And then if u still have a doubt look at the mark scheme. They only give u direct answers. They dont write each and every step.
Thats what my teachers advise me to do.

why this xtremepapers not opening papers link ???
 
Top