http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s04_qp_1.pdf
please anyone explain Q25 ASAP
please anyone explain Q25 ASAP
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)
The answer *is* A. D is totally wrong because they are in a same direction. Confirm it with your clock... these are both going clockwise.Hello people, i need to confirm something, for oct/nov 2002 the examiner report says for mcq no 13 that the answer is A (which does not make sense) however i have seen other people quoting the answer as C and others as D......so could i please have the link of a correct and verified marking scheme for that exam session....thanx soo much!
thanx i understood nowThe answer *is* A. D is totally wrong because they are in a same direction. Confirm it with your clock... these are both going clockwise.
C is wrong because couple is of forces that are opposite And *Equal*. Though the forces here are opposite, one is twice the other.
B is obviously wrong.
A, for this one, it isn't necessary for the forces to be on the circumference of the circle. It does fulfill the requirement of being a couple of forces.. they're equal, they're opposite.
Hope it helps
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w09_qp_11.pdf
Q.14, 15, 22, 26, 28, pretty please?
pleeeasseee helphas the solved explanation for Nov 2003 been uploaded?? If not, can someeoone pleeeaasee upload it...i need it real bad...thanx so much! May God bless you!
for polymeric materials ( ex rubber)....after the elastic limit and before the breaking point, a large increase in the Force cause a small increase in the extension...so A is the graph wich supports this idea..and besides u must know what is the shape of a force-extension graph for each type of material ( brittle, ductile, and polymeric)...HOPE I HELPED
November 2005
=============
Q1. B
Fact
Q2. C
Fact
Q3. D
volt = work/charge
kgm^2s^-2 / As
= kg ms^-2 s^-3 A^-1
Q4. B
Results are said to be precise if the values are within 1 mm of their mean. Accurate is how close the values obtained are to the true value. Here, none of them are within 1 mm to 895 mm.
Q5. C
Vo = (5*2*1) = 10 (principle volume value)
Vu = (0.01/5) + (0.01/2) + (0.01/1) * 10 = 0.17
So volume = 10 +/- 0.17
And mass = 25 +/- 0.1
Uncertainty in density = (0.17/10) + (0.1/25) * 2.5 = 0.05
Q6. C
The acceleration will decrease until it reaches 0
Q7. From 0 to x,
s = 0 + 0.5a * t1^2
s = 0.5a * t1^2
From h to x,
s = 0 + 0.5a * t2^2
For h - x,
h = 0.5a * t2^2 - 0.5a * t1^2
h = 0.5a (t2^2 - t1^2)
a = 2h / (t2^2 - t1^2)
Q8. A
Initially, as the force is 0, acceleration is 0 (F = ma)
Therefore the speed will initially be 0, as in all graphs
Once the force becomes a constant value, the acceleration is constant but non-zero, so the velocity increases linearly
9. D
Fact
10. A
Mass is always constant, so C and D are wrong
gravitation field on P = W/M (since mg = W)
= 1/1 = 1
on Q, it is one-tenth so 1/10 * 1 = 0.1
Weight of mass on Q = 1 * 0.1 = 0.1 N
Q11. A
Only acceleration will act and that too in direction XY only since its part of the vertical component
Q12. D
Clockwise = 20 * 0.4 = 8 Nm
Anti-clockwise = 10 * 0.6 + 100 * 0.1 = 16 Nm (don't forget the weight of the beam!)
Therefore we need a clockwise moment of 8 more Nm
(20 * x) = 8, x = 0.4m from the pivot, so D
13. A
Resultant torque = 45 N and resultant force = 60 N to the right
14. C
0.5 * 1400 * 30^2 = 630 kJ
15. B
Ep decreases linearly with height above the ground.
EP = mgh
If h is on the x-axis and EP on the y-axis, then the gradient mg would be a constant
Q16. C
Tension = mg sin θ = 10^3 sin 30 = 500 N (note: weight was already given, so need to multiply by 9.81)
Work = force * distance moved in direction of force = 500 * 5 = 2500 J
Q17. C
Fact. Heating a gas gives more K.E to the gas molecules so they hit the wall containers more often. Some statements, e.g. B are correct but aren't relevant to the question, so it's important
to read these type of questions carefully.
Q18. C
P(X) = P(Y)
ρgh = pgh
800 * g * h1 = 1200 * g * h2
800h1 = 1200 h2
C is the only answer which is correct for this equation
Q19. B
White sugar granules appear as white small crystals, obviously so it's crystalline. When something is melted quickly (i.e. supercooled) and appears to be sort of brittle, then it becomes
amorphous. So B. You need to learn the properties of crystalline, amorphous and polymeric solids well.
Q20. B
B is the net work done stretching the sample
Q21. C
E = FL/Ax (where x = extension and E = Young Modulus), rearranging to give 'x' as the subject gives us:
x = FL/AE (E is a constant which MUST remain the same because its the same material)
Half diameter = 1/4th of the area and quarter length = 1/4th of length
ratio of new x = (F * 0.25L) / (0.25A * E)
= 1
Therefore the extension remains the same, 8 mm.
Alternatively, you can use the spring constant to solve this:
60 = k * (8/1000)
k = 7500
Since the forces are the same,
F1 = F2
ke = kz (where z is the new extension)
7500 * (8/1000) = 7500 * z
z = 8 mm
Q22. D
If a wave is to be polarized it must be transverse
Q23. B
In A and C, the amplitude is marked incorrectly. In D, λ is actually the time period.
Q24. B
I α a^2 and I α f^2.
Rather than doing all the math to do this, compare the amplitude and frequency of the waves and use the formula to figure out this stuff:
If Q's amplitude is twice as much, the intensity will be four times as much.
If Q's frequency is half that of P, the intensity will be one-fourth.
Net change = 0, so the intensity remains the same.
Q25. C
λ in water = 1500/150 = 10m and λ in air = 300/150 = 2m
Q26. D
X and Y are adjacent anti-nodes, and they (as well as adjacent nodes) are 0.5λ apart.
Q27. C
Fact, from the definition of diffraction. Light bends when it passes through an aperture or narrow slit
Q28. A
x = λd/a
Halving λ also halves x so 0.75 mm.
Q29. C
Since the adjacent 1st orders are 60 apart, that means one 1st order from the undeviated beam is 30 apart.
1.15 * 10^-6 sin 30 = 1 * λ
λ = 575 nm
Q30. A
Electric field lines go from + to -, so the +ve particle will move down towards the -ve side.
Q31. A
Fd = VQ
F = (200 * 0.005) / 1.6 * 10^-19
F = 6.4 * 10^-15 N
Q32. B
Graph X = diode
Graphy Y = ohmic
Graph Z = lamp
Q33. D
Increasing the strain (i.e. extension) increases the length and reduces the cross-sectional area, and since R = ρL/A, this means R increases.
Q34. C
One way of doing this accurately is drawing a straight line from the origin and seeing which option is the closest, since R is the ratio of V:I. Or if you are too unsure about that, make an accurate scale with your ruler and calculate the values. That's a waste of time though.
Q35. B
Variable resistor = box with diagonal arrow through it
Fuse = box with straight line through it
LDR = box with 2 arrows "shining" onto it
Thermistor = box with a diagonal line through it, with an added small straight, horizontal line at the bottom
Q36. B
Total I = V/R = 6/450 = 0.0133... A
V through 180 resistor = 0.0133... * 180 = 2.4 V
Q37. C
Readings on both VT and VL are high, so the voltmeter readings must be high. Since the voltmeter is connected directly to the LDR, a high resistance indicates a high voltmeter reading (because V = IR). An LDR gives high resistance in the dark, so the light level should be low.
For VT, the thermistor is NOT connected directly to the voltmeter, but the fixed resistor is, so V = IR doesn't apply for the thermistor but for the fixed resistor instead. Decreasing the resistance on the thermistor will give a high VT reading (you can prove this using the potential divider formula). And a low resistance on the thermistor means a high temperature.
Q38. D
Emission of a β particles increase the proton number by 1 but doesn't affect the nucleon number.
Q39. B
Both particles will be deviated upwards, but the one closer will deviate more because it's closer.
Q40. D
To balance the equations, the nucleon and proton number of X must be 1 and 1 respectively. This is a proton.
For almost 10 years, the site XtremePapers has been trying very hard to serve its users.
However, we are now struggling to cover its operational costs due to unforeseen circumstances. If we helped you in any way, kindly contribute and be the part of this effort. No act of kindness, no matter how small, is ever wasted.
Click here to Donate Now