9702 June 2012 Paper 12 Worked Solutions | A-Level Physics
Paper 12
1 C 11
B 21 C 31 C
2 D 12
D 22 C 32 C
3 D 13
A 23 C 33 D
4 B 14
B 24 B 34 B
5 B 15
D 25 C 35 D
6 A 16
D 26 D 36 D
7 A 17
B 27 C 37 D
8 D 18
D 28 D 38 C
9 A 19
B 29 C 39 B
10 A 20
D 30 B 40 B
Notes for some specific questions:
3 - Ans: D. {Detailed explanations for this question is available as Solution 1117 at Physics 9702 Doubts | Help Page 240 - http://physics-ref.blogspot.com/2016/07/physics-9702-doubts-help-page-240.html}
4 – Ans: B. {Detailed explanations for this question is
available as Solution 287 at Physics 9702 Doubts | Help Page 48 - http://physics-ref.blogspot.com/2015/01/physics-9702-doubts-help-page-48.html}
5 – Ans: B.
A mass is dropped from rest, and falls through a distance of 2.0 m in a vacuum. An observer records the time taken for the mass to fall through this distance using a manually operated stopwatch and repeats the measurements a further two times.6 - Ans: A.
The diagram shows two complete pulses on the screen of a cathode-ray oscilloscope. A grid of 1 cm squares covers the screen.
7 - Ans: A. {Detailed explanations for this question is available as Solution 518 at Physics 9702 Doubts | Help Page 101 - http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-101.html}
8 – Ans: D.
9 – Ans: A. Brick is falling, so
height decreases with time. [C and D are incorrect] Gradient of the graph gives
speed of fall of brick. Due to gravity, there is an acceleration of 9.81ms-2,
so speed keeps on increasing until it reaches the ground. So, gradient is not
constant. [B is incorrect]
10 - Ans: A. {Detailed explanations for this question is available as Solution 947 at Physics 9702 Doubts | Help Page 195 - http://physics-ref.blogspot.com/2015/09/physics-9702-doubts-help-page-195.html}
11 - Ans: B. {Detailed explanations for this question is available as Solution 513 at Physics 9702 Doubts | Help Page 100 - http://physics-ref.blogspot.com/2015/03/physics-9702-doubts-help-page-100.html}
12 - Ans: D. {Detailed explanations for this question is available as Solution 932 at Physics 9702 Doubts | Help Page 192 - http://physics-ref.blogspot.com/2015/08/physics-9702-doubts-help-page-192.html}
13 – Ans: A. {Detailed explanations for this question is
available as Solution 425 at Physics 9702 Doubts | Help Page 80 - http://physics-ref.blogspot.com/2015/03/physics-9702-doubts-help-page-80.html}
14 – Ans: B. {Detailed explanations for this question is available as Solution 974 at Physics 9702 Doubts | Help Page 201 - http://physics-ref.blogspot.com/2015/09/physics-9702-doubts-help-page-201.html}
15 – Ans: D. {Detailed explanations for this question is available as Solution 769 at Physics 9702 Doubts | Help Page 155 - http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-155.html}
16 - Ans: D. {Detailed explanations for this question is available as Solution 813 at Physics 9702 Doubts | Help Page 163 - http://physics-ref.blogspot.com/2015/06/physics-9702-doubts-help-page-163.html}
17 - Ans: B. {Detailed explanations for this question is available as Solution 557 at Physics 9702 Doubts | Help Page 109 - http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-109.html}
20 - Ans: D. {Detailed explanations for this question is available as Solution 1062 at Physics 9702 Doubts | Help Page 223 - http://physics-ref.blogspot.com/2015/11/physics-9702-doubts-help-page-223.html}
22 - Ans: C. {Detailed explanations for this question is available as Solution 332 at Physics 9702 Doubts | Help Page 58 - http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-58.html}
16 - Ans: D. {Detailed explanations for this question is available as Solution 813 at Physics 9702 Doubts | Help Page 163 - http://physics-ref.blogspot.com/2015/06/physics-9702-doubts-help-page-163.html}
17 - Ans: B. {Detailed explanations for this question is available as Solution 557 at Physics 9702 Doubts | Help Page 109 - http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-109.html}
20 - Ans: D. {Detailed explanations for this question is available as Solution 1062 at Physics 9702 Doubts | Help Page 223 - http://physics-ref.blogspot.com/2015/11/physics-9702-doubts-help-page-223.html}
22 - Ans: C. {Detailed explanations for this question is available as Solution 332 at Physics 9702 Doubts | Help Page 58 - http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-58.html}
23 - Ans: C. {Detailed explanations for this question is available as Solution 361 at Physics 9702 Doubts | Help Page 64 - http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-64.html}
24 - Ans: B. {Detailed explanations for this question is available as Solution 476 at Physics 9702 Doubts | Help Page 92 - http://physics-ref.blogspot.com/2015/03/physics-9702-doubts-help-page-92.html}
25 - Ans: C. {Detailed explanations for this question is available as Solution 363 at Physics 9702 Doubts | Help Page 65 - http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-65.html}
26 – Ans: D. Should allow for
reflection. Total distance = 2(150) = 300m. Speed = 3x108ms-1.
So, time = 1x10-6s = 1μs.
27 - Ans: C. {Detailed explanations for this question is available as Solution 640 at Physics 9702 Doubts | Help Page 127 - http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-127.html}
28 - Ans: D. {Detailed explanations for this question is available as Solution 166 at Physics 9702 Doubts | Help Page 28 - http://physics-ref.blogspot.com/2014/11/physics-9702-doubts-help-page-28.html}
29 - Ans: C. {Detailed explanations for this question is available as Solution 366 at Physics 9702 Doubts | Help Page 66 - http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-66.html}
30 – Ans: B.
A standing sound wave is set up between a loudspeaker and a wall. 31 - Ans: C. {Detailed explanations for this question is available as Solution 678 at Physics 9702 Doubts | Help Page 137 - http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-137.html}
32 - Ans: C. {Detailed explanations for this question is available as Solution 1114 at Physics 9702 Doubts | Help Page 239 - http://physics-ref.blogspot.com/2016/06/physics-9702-doubts-help-page-239.html}
33 – Ans: D. R=ρL/A. A is incorrect since the charged particles
(ions and electrons) are already present in the wire. B is incorrect because
the wire with the smaller diameter, and hence, smaller cross-sectional area
resulting in a higher resistance. So, for same current to flow in both of them
[I=V/R], a larger potential difference should be applied to the smaller wire,
causing the average velocity of the charged particles to be faster in the
smaller wire. C incorrect because larger diameter > smaller resistance >
smaller pd required > less energy provided to charged particles.
35 - Ans: D. {Detailed explanations for this question is available as Solution 364 at Physics 9702 Doubts | Help Page 65 - http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-65.html}
36 - Ans: D. {Detailed explanations for this question is available as Solution 426 at Physics 9702 Doubts | Help Page 81 - http://physics-ref.blogspot.com/2015/03/physics-9702-doubts-help-page-81.html}
37 – Ans: D.{Detailed explanations for this question is available as Solution 789 at Physics 9702 Doubts | Help Page 159 - http://physics-ref.blogspot.com/2015/06/physics-9702-doubts-help-page-159.html}
38 - Ans: C. {Detailed explanations for this question is available as Solution 182 at Physics 9702 Doubts | Help Page 29 - http://physics-ref.blogspot.com/2014/11/physics-9702-doubts-help-page-29.html}
Explanations
have been provided for questions that were found to be more difficult.
If you are having other doubts that have not been explained here, you
may ask your questions through comments.
How about Q8 and 18 ?
ReplyDeleteThank you
Explanation for Qu8 is already available above.
ReplyDelete18 – Ans: D. Power produced by generator = VI = 230 x 32 = 7360W. Power = Work done / time. Taking KE = PE. Power available in water = mgh / t = (m/t)gh = (200)x9.81x8 = 15696W. Efficiency = 7360/15696 = 0.468 = 47%.
please explain 38
ReplyDeleteQu 38 has been explained
DeleteExplanations for Q23 has been added
ReplyDeleteQ25 has now been explained
ReplyDeleteExplanations for Q29 is now available
ReplyDelete9702/13/M/J/12?
ReplyDeleteI want worked Solution for this paper.
the paper would be publish later.
Deletein the meantime, you may ask for the specific questions from that paper
May June 2013 varient 13.
ReplyDeleteQuestion# 12?
check at
Deletehttp://physics-ref.blogspot.com/2015/01/9702-june-2013-paper-13-worked.html
Q36 solution please?
ReplyDeleteQuestion 36 solution has been added
Deletequestion 7?
ReplyDeleteQ7 is now explained
DeleteFor question 13, why are we subtracting the fricition from the 2kg box's weight?whereas the friction is acting on the 8kg box?
ReplyDeleteThe 8kg box and the 2kbg box form part of a single system. If the friction on the 8kg box is greater, this also causes the 2kg box to fall with a smaller acceleration, and if it is large enough, the 2kg may even remain still.
Delete+ it is NOT being subtracted from the 2kg box. The weight of the 2kg box causes an acceleration downwards, and on the horizontal surface, this acceleration is to the right. Friction, which opposes motion, is to the left.
So, both are forces that area acting on the whole system
24????
ReplyDeleteQuestion 24 is explained
Deleteq27
ReplyDeleteExplained
Delete11
ReplyDeleteQ11 has been explained
Deleteq35 mate?
ReplyDeleteIncluded
Deleteq17 please ?
ReplyDeleteQuestion 17 is now explained
DeleteCan you provide a diagram from q 15. It's confusing, where exactly is the torque acting?
ReplyDeleteI mean, how does the clockwise direction maintain equilibrium? I don't get it.
The explanations have been updated
DeleteThank you. You are doing a wonderful job!
DeleteMay June 2012 variant 11 questions - 36, 34, 24 please thanks!
ReplyDeleteFor Q36, see solution 762 at
Deletehttp://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-154.html
please explain questions 8,12,15,23,31 of may 2012 variant 11
ReplyDeletethanks :)
For Q8, see solution 784 at
Deletehttp://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-158.html
For Q12, see solution 178 at
http://physics-ref.blogspot.com/2014/11/physics-9702-doubts-help-page-29.html
For Q15, see solution 777 at
http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-157.html
For Q23, see solution 334 at
http://physics-ref.blogspot.com/2015/02/physics-9702-doubts-help-page-58.html
thank you for the above explanations. explain q31 of the same variant aswell
ReplyDeleteSee solution 793 at
Deletehttp://physics-ref.blogspot.com/2015/06/physics-9702-doubts-help-page-160.html
Question 16, why is it not C? Initial acceleration should be 9.81ms^-2 right? And then this decreases as the speed increases since resultant forces (viscous drag) increase so the gradient should fall. Also, when do we know if value of g is positive or negative?
ReplyDeleteDetails have been added for Q16
DeleteOctober/November 2012 paper13 qu25. Could you please explain this question? I found D as the answer by finding the spring constant of each wire and then multiplying it by 2 since the lift is supported by two cables in parallel and then substituted my values in E=kL/A, where A is the total cross sectional area of both wires. It is the wrong answer, however.
ReplyDeleteSee solution 824 at
Deletehttp://physics-ref.blogspot.com/2015/06/physics-9702-doubts-help-page-164.html
question 20 pls
ReplyDeleteAdded
Deletecan you explain Q.32 ?
ReplyDeleteAdded
Deleteyour question 33 explanation is incorrect. isn't it ?
ReplyDeleteLet me know what exactly you believe to be incorrect.
DeleteQ3 please!
ReplyDeleteAdded
DeleteQ no.40
ReplyDeleteexplanation added above
Delete