Physics Paper 12/MJ/2015 Answers and Questions!

[Aly Emran]

Stop,wait a minute,i guess the ordering of the questions is off a bit,because all 3 of us got A in Q32(look in the chat) and maybe this question was not 32,and maybe another.Are you 100% positive it was B?Because such a silly mistake seems highly unlikely.

Hahahaha....Dude order of question isnt correct.... Facepalm
Maybe its not Q32
I just wrote them.... Itnay saray yaad rakhna bhi bari baat ha

 

[Aly Emran]

Abhi nai,on 11 August IA :')

In Shaa Allah

 

[asadalam]

Dude order of question isnt correct.... Facepalm xD
I just wrote them.... Itnay saray yaad rakhna bhi bari baat ha

So maybe it is A then?Cuz like i said it'd be highly unlikely for all 3 of us to make such a silly mistake.And yeah,salute to your memory

 

[Aly Emran]

So maybe it is A then?Cuz like i said it'd be highly unlikely for all 3 of us to make such a silly mistake.And yeah,salute to your memory

Well I wont make this mistake
Otherwise I should hang myself
Maybe its Q30 and not 32

 

[asadalam]

Well I wont make this mistake
Otherwise I should hang myself
Maybe its Q30 and not 32

Lol i dont match with your 30 as well I have B you have A

 

[Aly Emran]

Lol i dont match with your 30 as well I have B you have A

Your're actually checking them?
Lol i dont remember the sequence so... Lets leave this topic... Otherwise we might think we have done some huge blunders
And my 30 isnt A, i copied ahmed's answers and wrote comments in front of them... On 30, i wrote idr which means i dont remember what was Q30

 

[asadalam]

Your're actually checking them?
Lol i dont remember the sequence so... Lets leave this topic... Otherwise we might think we have done some huge blunders
And my 30 isnt A, i copied ahmed's answers and wrote comments in front of them... On 30, i wrote idr which means i dont remember what was Q30

Oh acha,chalo khair hai I just remembered the questions and recalled my answers on the first post rather than check from my ans,so i guess i was concerned when i didnt notice the ordering wasnt right
Lets get back to chilling then

 

[Sifat Bin Quadery]

Guys pls check if the answers are right:
(According to the list given above)
1. C
2. D
3. 4%
4. C.... Gradient reducing
5. C
6. S actual and t smaller
7. D
8. C (12s)
9. Constant gradient with a st line thru 0
10. Acceleration increase then become zero
11. D ( share momentum but lose KE)
12. C
13. B
14. B 76000
15. D
16. D
17. C 450
18. 4.6
19. A
20. A the pull of book on the earth
21. 150
22. 1.1 m
23. Max and min observed
24. B just beyond S
25. Forgot
26. C
27. A
28. Max 9 min 0
29. 0.25
30. A
31. D
32. B
33. B
34. Root 2 w
35. C ( got it wrong)
36. B
37. B
38. C
39. C ( nucleon number )

 

[Aly Emran]

Guys pls check if the answers are right:
(According to the list given above)
1. C
2. D
3. 4%
4. C.... Gradient reducing
5. C
6. S actual and t smaller
7. D
8. C (12s)
9. Constant gradient with a st line thru 0
10. Acceleration increase then become zero
11. D ( share momentum but lose KE)
12. C
13. B
14. B 76000
15. D
16. D
17. C 450
18. 4.6
19. A
20. A the pull of book on the earth
21. 150
22. 1.1 m
23. Max and min observed
24. B just beyond S
25. Forgot
26. C
27. A
28. Max 9 min 0
29. 0.25
30. A
31. D
32. B
33. B
34. Root 2 w
35. C ( got it wrong)
36. B
37. B
38. C
39. C ( nucleon number )

1. Correct
2. Correct
3. Not sure but many said 4% is correct
4. Again not sure but... Majority selected C
5. Correct
6. Correct
7. Correct
8. Correct
9. Correct
10. not sure about this but chances is that your might be incorrect. Reason, 9.81ms-2 is still acting even if rocket isnt accelerating. So it cant be zero after 5s
11. Correct
12. Might be correct. Even I marked C
13. Correct
14. Correct
15. Correct
16. Not sure about this one... Many said its either A or D
17. Correct
18. Correct
19. Incorrect. It was 82%
20. Incorrect. Since book was pushing and the other force should be opposite and different object provides reaction
21. Not sure... Its either 150 or 260
22. Correct
23. Correct
24. Correct
25. The answer was diameter
26. Correct
27. Correct
28. Incorrect. It was 5-2
29. Correct
30. Correct
31. Not sure, even I marked D
32. Correct
33. Correct
34. Not confirmed yet
35. Incorrect
36. Correct
37. Incorrect
38. Correct
39. It was 1alpha and 2 beta, might be correct. Dont remember the option

I dont remember the last question...

 

[Xtreamer]

Guyz what was WIDTH 2w or square root 2 . And for coherence or diffraction and interference. I think it should be coherent becauze first step is coherent , second step is DIFRACTION and interference

Yeah I did coherence too

 

[hamzashariq]

I did constant, constant for Q10. When the fuel burns out, there will be a constant acceleration equal to g, and when the fuel is burning, it is providing a constant force,and so the sum of that force and g must be constant.

 

[hamzashariq]

34) I think the answer was 2w, since it was a tube, it was hollow from the inside, and so its cross sectional area was equal to 2pi r * w.

 

[Xtreamer]

I did constant, constant for Q10. When the fuel burns out, there will be a constant acceleration equal to g, and when the fuel is burning, it is providing a constant force,and so the sum of that force and g must be constant.

I did constant F too...do u remember the choices?

 

[Safiya Ramzy]

Yani aap bhi meray saath hi ho :/
Meray bhi 8marks lost

Hi I noticed that for the fish question, when they asked us to find the gain in energy of the fish, you answered D. I think it's because you added the gain in Kinetic energy of the fish as well. However, the question stated that it was being pulled up at constant velocity, therefore, there would be no gain in kinetic energy. So we simply had to find only the gain in gravitational potential energy and the answer would be C. I could be wrong Tell me what you think x

 

[Aly Emran]

Hi I noticed that for the fish question, when they asked us to find the gain in energy of the fish, you answered D. I think it's because you added the gain in Kinetic energy of the fish as well. However, the question stated that it was being pulled up at constant velocity, therefore, there would be no gain in kinetic energy. So we simply had to find only the gain in gravitational potential energy and the answer would be C. I could be wrong Tell me what you think x

This isnt me who did this.... I've discussed this with someother super genius here..... They even marked D

 

[asadalam]

Hi I noticed that for the fish question, when they asked us to find the gain in energy of the fish, you answered D. I think it's because you added the gain in Kinetic energy of the fish as well. However, the question stated that it was being pulled up at constant velocity, therefore, there would be no gain in kinetic energy. So we simply had to find only the gain in gravitational potential energy and the answer would be C. I could be wrong Tell me what you think x

It was at rest and then its speed changed so it gained KE.Its 100% D/450

 

[Safiya Ramzy]

It was at rest and then its speed changed so it gained KE.Its 100% D/450

That's not what I remember. It said that the farmer was lifting it at a constant velocity of 1.1 m/s

 

[Aly Emran]

That's not what I remember. It said that the farmer was lifting it at a constant velocity of 1.1 m/s

It was at rest and then its speed changed so it gained KE.Its 100% D/450

Okay lets be practical!
Suppose u are holding a fish in ur hand... You raise it up... Do you raise it wit hconstant speed? And how can farmer know that he is lifting at constant speed? The word REST was mentioned there i am 100% sure

PS asadalam she is talking about the fish question
450J answer was of rectangle block tilted at 90 degree

 

[asadalam]

Okay lets be practical!
Suppose u are holding a fish in ur hand... You raise it up... Do you raise it wit hconstant speed? And how can farmer know that he is lifting at constant speed? The word REST was mentioned there i am 100% sure

PS asadalam she is talking about the fish question
450J answer was of rectangle block tilted at 90 degree

Oh right but yeah we had to include both GPE and KE in the ans

 

[tahakay]

Your 30 is wrong , ans for 30 was B (Potential difference is other forms converted to electrical).