MisterE1
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#921
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#921
Btw I keep editing my post with little things is no-ones noticed lol
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MSI_10
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#922
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#922
(Original post by cooldudeman)
Agreed. What do you think you got?

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I definitely got at least 8 wrong.. I'm gonna throw (or take out) another 6 for the sake of it and say I got 61 ish.. Hard to tell because people are still debating about the max emf question, the sine wave etc. Also, I put 2.6 radians (which is 150 degrees) instead of 5PI/6 so unsure if I will lose a mark for that even though i am technically correct..

how about yourself?
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MSI_10
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#923
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#923
(Original post by cottonsocks0_0)
but this paper is easier than any paper before?i think?
Hmm.. Most people found it hard in my coll, many of them saying they flopped completely, ran out of time for section A etc and even on here ppl are still discussing the EMF question..

And it's Unit 4. Max it has been before for 120 UMS is 63.. Maybe 64 for this paper but I wouldn't be surprised if it was lower
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MisterE1
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#924
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#924
(Original post by MSI_10)
I definitely got at least 8 wrong.. I'm gonna throw (or take out) another 6 for the sake of it and say I got 61 ish.. Hard to tell because people are still debating about the max emf question, the sine wave etc. Also, I put 2.6 radians (which is 150 degrees) instead of 5PI/6 so unsure if I will lose a mark for that even though i am technically correct..

how about yourself?
I'm certain physics papers always want decimals over fractions, and when it is a nice fraction such as 5/6 they usually accept both.

I'm only saying this from doing past papers and reading through the mark schemes!
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cooldudeman
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#925
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#925
(Original post by MSI_10)
I definitely got at least 8 wrong.. I'm gonna throw (or take out) another 6 for the sake of it and say I got 61 ish.. Hard to tell because people are still debating about the max emf question, the sine wave etc. Also, I put 2.6 radians (which is 150 degrees) instead of 5PI/6 so unsure if I will lose a mark for that even though i am technically correct..

how about yourself?
Ahh thats really good.
Pshh I prob lost 6marks on section A. I defo got q5 all right and q1 (even tho im still seeing people saying 1500 for a part in q1...). So I think I got 60. I actually have a chance of getting a*. Unit ****ing 5 will judge it

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saba146
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#926
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(Original post by MisterE1)
Btw I keep editing my post with little things is no-ones noticed lol
there was a multiple choice question about moving a negative ion in a electric field?

and the one about the rotating coil
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MSI_10
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#927
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#927
(Original post by saba146)
there was a multiple choice question about moving a negative ion in a electric field?
was this the one regarding line PQ and which statement is correct?

Was it that if the ion is on the line PQ no potential (answer D iirc) or something like that?

(Original post by cooldudeman)
Ahh thats really good.
Pshh I prob lost 6marks on section A. I defo got q5 all right and q1 (even tho im still seeing people saying 1500 for a part in q1...). So I think I got 60. I actually have a chance of getting a*. Unit ****ing 5 will judge it

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LOL I'm going to post and edit that unofficial mark scheme and update that! 1500Hz in SHM, you crazy!? :P and 60 is a very respectable score so well done, this is the hardest A level unit in my opinion. I got a D back in Jan but hard work pays off..

Thankfully, Unit 5 is much easier and less complex, just a lot to memorise.. Lack of past papers as well so
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cooldudeman
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#928
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#928
Ahh man the ratio of r was 14? I got 3.7 and did everyone ise T= mg+ mv2/r??

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saba146
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#929
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#929
(Original post by MSI_10)
was this the one regarding line PQ and which statement is correct?

Was it that if the ion is on the line PQ no potential (answer D iirc) or something like that?



LOL I'm going to post and edit that unofficial mark scheme and update that! 1500Hz in SHM, you crazy!? :P and 60 is a very respectable score so well done, this is the hardest A level unit in my opinion. I got a D back in Jan but hard work pays off..

Thankfully, Unit 5 is much easier and less complex, just a lot to memorise.. Lack of past papers as well so

it was rev/min not seconds
25 rev/sec so 1500 rev/min
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The H
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#930
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#930
(Original post by cooldudeman)
Ahh man the ratio of r was 14? I got 3.7 and did everyone ise T= mg+ mv2/r??

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Yeah and I also got 3.7
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cooldudeman
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#931
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#931
(Original post by The H)
Yeah and I also got 3.7
Why does it say 14 on MS? I hope we are right. Damnnnn

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saba146
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#932
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#932
(Original post by cooldudeman)
Ahh man the ratio of r was 14? I got 3.7 and did everyone ise T= mg+ mv2/r??

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i got 3.7 and did the same as you for the tension! i hope thats right
i used the mass of the earth and the radius of the earth which was given in the formula book to find the radius of the moon
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LolaJenson
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#933
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#933
(Original post by cooldudeman)
Why does it say 14 on MS? I hope we are right. Damnnnn

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i saw this exact same question on a past paper and im prettttty sure it was 3.whatever

not 100% but pretty damn sure
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MSI_10
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#934
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#934
1)t root2, 2)460 and current its greater that 0.26, 3)path of electron was A the arrow pointing upwards, 4)potential was at mars, not the moon (but whatever) or something was -13, 5)maximum value of tension was 24 6) kinetic energy of p was greater than q but potential energy was less that q 7) capacitance graph question was D, 8) fe>fm>fs(i think that is Fe>Fs>Fm) 9) ratio of y/d=1/3
10) R earth/Rmoon=14
11)which one is incorrect: when spring is compressed &suspended,it has minimum PE 12) which one is incorrect: change of momentum=zero 13)moving horizontally,Blv …
13) Capacitance value of 0.02F for one question forgot which was, answer choice was B IIRC


1a)define shm:
acceleration is proportinal to displacement, and acceleration acts toward equilibrium (2)
acceleration was rounded to -0.43
frequency of pendulum = 0.503 3s.f (3)
time for oscilations to be in phase again = 38 (3)


2) voltage = 30,000 (1)
b) (3) i think this was the capacity was increase from X to Y. find the energy stored? wasnt this the time taken for the spark to be produced?
yes, i think it was similar:

b) i think this was the capacity was increase from X to Y.time taken for the spark to be produced after the last discharge?
then Q=CV, then Q/Current = time was ~ 3.46s????(3.46 days……rate is ?A a day)

you had to work out the charge stored and then use the current they gave you to find the time??
c) time taken for discharge will increase because time constant increases (2)
d) flash is brighter because more energy stored (2)




3) 2 conditions when no force is exerted on the partcle (2)
field is parallel to velocity
particle is stationary

b) prove momentum is proportional to radius= mv^2/r = BQv , mv = BQr --> mv = kr

b ii) speed of particle was definitely around 8.7 X 10 ^ 7

c)time taken for partile to go through 1 dee = ~6.8x10^-8
d)show the time taken is independent of radius = 2pim/bq (3)
kinetic energy im MEV = 2.44 (3)

The six marker was Question 4


1. gravity always attractive
2. electric attractive/repulsive
3. both follow inverse square for Force
4. both follow inverse for potential
5. gravity uses mass
6. electric uses charge
7. only electric fields can be shielded
8. only electric fields depend on medium between charges
9. gradient of potential vs distance graph gives field strength
10. potential definition for both revolves around bringing a mass/charge from infinity to a certain point in a field and is zero at infinity

angle for max emf = 60 degrees -- this is at 90 degrees to the plane as emf = BANw sin(wt) therefore max emf is when sin(wt) =1, there for wt (which is the angle) = 90, 90-30 = 60 degreed
angle for max flux linkage = 5pi/6 = 2.62 radians -- this is at 0 degrees = 180 degrees, and N(PHI) = BAN cos(THETA), so max is when cos(THETA) = 1 so theta = 180, 180-39 = 150 degrees = 5pi/6
gradient of graph = emf (1)


drawing a graph (2) Positive Sine graph
peak voltage (3) I got 0.55 for peak to peak voltage then divided by 2 to get 27.5V but there is no set agreement on what the value is for this answer yet..
calculate flux density = 0.26 (2)( got 0.25 here) I got 0.25 as well


My adjustments made in bold, whoever remembers a section A question not listed, throw it in!
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MisterE1
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#935
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(Original post by The H)
Yeah and I also got 3.7
As I remember the question:

Mass of the earth is 81 x mass of the moon
Gravitational field strength on the earth = 9.8
Gravitational field strength on the moon = 1.8

g = GM/r^2.

9.8 = 81GM/re^2

1.8 = GM/rm^2

Re-arrange and you get re^2/rm^2 = ~14.89
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marcolliwright
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#936
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#936
(Original post by saba146)
i got 3.7 and did the same as you for the tension! i hope thats right
i used the mass of the earth and the radius of the earth which was given in the formula book to find the radius of the moon
3.7 here as well....
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saba146
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#937
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#937
1)t root2,
2)460 and current its greater that 0.26,
3)path of electron was A the arrow pointing upwards,
4)potential at moon or something was -13,
5)maximum value of tension was 24
6) kinetic energy of p was greater than q but potential energy was less that q
7) capacitance graph question was D,
8) fe>fm>fs(i think that is Fe>Fs>Fm)
9) ratio of y/d=1/3
10) R earth/Rmoon=3.7
11)which one is incorrect: when spring is compressed &suspended,it has minimum PE
12) which one is incorrect: change of momentum=zero
13)moving horizontally,Blv …
14)rotating coil was A
15) Capacitance value of 0.02F for one question forgot which was, answer choice was B IIRC
16) units of impulse = kgms-1
17) momentum question when the 2 trolleys collided?anyone remeber the answer??

8 MORE MULTIPLE CHOICE QUESTIONS THEN DONE!

SECTION B IS COMPLETE
1a)define shm:
acceleration is proportinal to displacement, and acceleration acts toward equilibrium (2)
acceleration was 0.4
frequency of pendulum = 0.503 3s.f (3)
1500 revs per minute (2)
time for oscilations to be in phase again = 38 (3)
TOTAL = 12

2) voltage = 30,000 (1)
b) (3) i think this was the capacity was increase from X to Y. find the energy stored? wasnt this the time taken for the spark to be produced?
yes, i think it was similar:

b) i think this was the capacity was increase from X to Y.time taken for the spark to be produced after the last discharge?
then Q=CV, then Q/Current = time was ~ 3.46s

you had to work out the charge stored and then use the current they gave you to find the time??
c) time taken for discharge will increase because time constant increases (2)
d) flash is brighter because more energy stored (2)
TOTAL = 7

3) 6 marker on fields
1. gravity always attractive
2. electric attractive/repulsive
3. both follow inverse square for Force
4. both follow inverse for potential
5. gravity uses mass
6. electric uses charge
7. only electric fields can be shielded
8. only electric fields depend on medium between charges
9. gradient of potential vs distance graph gives field strength
10. potential definition for both revolves around bringing a mass/charge from infinity to a certain point in a field and is zero at infinity
TOTAL = 6

4) 2 conditions when no force is exerted on the partcle (2)
field is parallel to velocity
particle is stationary
b) out of the plane of the paper
b) prove momentum is proportional to radius= mv^2/r = BQv , mv = BQr --> mv = kr
the speed of particle=8.7x107
c)time taken for partile to go through 1 dee = ~6.8x10^-8
d)show the time taken is independent of radius = 2pim/bq (3)
kinetic energy im MEV = 2.44 (3)
TOTAL = 15

angle for max emf = 60 degrees -- this is at 90 degrees to the plane as emf = BANw sin(wt) therefore max emf is when sin(wt) =1, there for wt (which is the angle) = 90, 90-30 = 60 degreed
angle for max flux linkage = 5pi/6 = 2.62 radians -- this is at 0 degrees = 180 degrees, and N(PHI) = BAN cos(THETA), so max is when cos(THETA) = 1 so theta = 180, 180-39 = 150 degrees = 5pi/6
gradient of graph = emf (1)


drawing a graph (2) Positive Sine graph
peak voltage (3)
calculate flux density = 0.26 (2)( got 0.25 here
TOTAL= 10
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cooldudeman
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#938
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#938
(Original post by saba146)
i got 3.7 and did the same as you for the tension! i hope thats right
i used the mass of the earth and the radius of the earth which was given in the formula book to find the radius of the moon
Thank god

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MSI_10
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#939
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#939
(Original post by saba146)
it was rev/min not seconds
25 rev/sec so 1500 rev/min

Erm yeah I agree, never suggested otherwise I was on about the mark scheme on this thread showing the answer to Q 5 at the start of Q 1 which was a mistake.

What was the question about the -ve ion?
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LolaJenson
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#940
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#940
(Original post by cottonsocks0_0)
1)t root2,
2)460 and current its greater that 0.26,
3)path of electron was A the arrow pointing upwards,
4)potential at moon or something was -13,
5)maximum value of tension was 24
6) kinetic energy of p was greater than q but potential energy was less that q
7) capacitance graph question was D,
8) fe>fm>fs(i think that is Fe>Fs>Fm) 9) ratio of y/d=1/3
10) R earth/Rmoon=14
i think its the 3.7
11)which one is incorrect: when spring is compressed &suspended,it has minimum PE
12) which one is incorrect: change of momentum=zero
13)moving horizontally,Blv …


1a)define shm:
acceleration is proportinal to displacement, and acceleration acts toward equilibrium (2)
acceleration was 0.4
frequency of pendulum = 0.503 3s.f (3)
1500 revs per minute (2)
time for oscilations to be in phase again = 38 (3)


2) voltage = 30,000 (1)
b) (3) i think this was the capacity was increase from X to Y.time taken for the spark to be produced after the last discharge?
then Q=CV, then Q/Current = time was ~ 3.46s????(3.46 days……rate is ?A a day)

you had to work out the charge stored and then use the current they gave you to find the time??
c) time taken for discharge will increase because time constant increases (2)
d) flash is brighter because more energy stored (2)


3) (6) marker on fields:
1. gravity always attractive/ electric attractive/repulsive
2. both follow inverse square for Force
3. both follow inverse for potential
4. gravity uses mass/ electric uses charge
5. only electric fields can be shielded
6. only electric fields depend on medium between charges
7. gradient of potential vs distance graph gives field strength
8. potential definition for both revolves around bringing a mass/charge from infinity to a certain point in a field and is zero at infinity

4) 2 conditions when no force is exerted on the partcle (2)
field is parallel to velocity
particle is stationary
b) prove momentum is proportional to radius= mv^2/r = BQv , mv = BQr --> mv = kr
the speed of particle=1.4*10^7(not sure)
c)time taken for partile to go through 1 dee = ~6.8x10^-8

d)show the time taken is independent of radius = 2pim/bq (3)
kinetic energy im MEV = 2.44 (3)


angle for max emf = 60 degrees (1)
5pi/6 (2)
gradient of graph = emf (1)


drawing a graph (2) Positive Sine graph
peak voltage (3)
calculate flux density = 0.26 (2)( got 0.25 here)

[can't remember anymore]


Are you guys sure the marks (in the brackets) are correct for all of question 1?

PS i edited it to make it more simple in places xD
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