(I am not giving any guarantee that this is correct. It is based on my faulty memory and the other responses here.)
SECTION A
Q1 Units (3)
Power AV
Coulomb - As
Conductance - AV^-1
Q2 Refractive Index (2)
3x10^8/1.7= 1.8x10^8
Q3 Potential Divider (2)
(4.5 / 280) * 40 = 0.64V
Q4 Bird Chirrup
Aspects of Bird Song Wave (2)
High frequency, followed by low frequency then high frequency again, averaging around 3kHz.
Chirrup lasts 0.5 seconds.
Number of oscillations (2)
3000 oscillations per second * 0.5 seconds = 1500 oscillations.
Q5 Waveforms of Sounds
Logarithmic scale? (1)
Increases by a multiple of 10 each time.
Estimate of highest music frequency (1)
350Hz
Estimate of bandwidth of human speech (1)
10kHz - 100Hz = 9900Hz
Q6 Lenses
Reading Glasses - Near point/curvature (2)
1/1.25 = 0.8D
Reading Glasses - Minimum power (3)
4.0D - 0.8D = 3.2D
Q7 Current Voltage Resistance
Find average current (2)
Average P.D is 2.6 V (52 blocks, *0.5/10 = 2.6V)
Resistance is 5 ohms
V=IR, I = V/R
I = 2.6/5 = 0.52A (will probably accept 0.5A)
Find total charge (2)
10 hours = 36000 seconds.
0.52A
Q =It = 0.52 * 36000 = 18720 (18000 if A = 0.5A)
* I believe there was another question here regarding a description of the effects of temperature, not sure? I think it was a 3 marker, and it basically just wanted a higher temperature means a longer working life time and higher voltages at all times.
=== 20 marks ===
SECTION B
Q8 Conductance and resistance
Non- ohmic conductor? (1)
I is not proportional to V, so resistance isn't constant.
Fill in the table (2)
3.14ohms, 20.somethingohms, something or other Watts.
Find length of wire (3)
0.0018m (awrt 0.002m, 1.8cm).
Resistivity ratio (2)
roughly 6.7
Temperature increase effect on resistivity (3)
Higher temperature leads to more movement of ions which mean that electrons find it harder to move through material. As electrons are charge carriers it means it is harder for them to move through.
Q9 Materials
YM Graphs (3)
D,A,B.
Calculation of YM (2)
Can't remember? I think the answer was 40GPa.
Alloys and Microscopic Properties (6)
For crane - A. Has highest resistance to stress so when under a large stress (ie from a weight attached) will not deform plastically. This is because pinned guest atoms prevent the movement of dislocations.
For crumple zone - D. Least stiff (for this, imagine you have some paper and some titanium. The paper crumples more, and is less stiff). This is due to fewer pinned dislocations (?).
Q10 Imaging
Levels=16? (1)
2^4 = 16
log2(16) = 4
Size of image (2)
500*300*4 = 600,000 bits
= 75000 bytes
Size of video (2)
90*5*75000 = 3.375*10^7 bytes.
Magnification (2)
Can't remember. Something very high.
Resolution (1)
Can't remember. Something very low as far as I can remember.
Calculate sensitivity at 25nm (2)
I got 670pA/nm, but I would assume ±100 or so depending on which gradient you got.
Graph of AFM (2)
Flat lines at 100pA, then curved peaks on dotted lines up to 260pA.
How image is produced (1)
High points are mapped to lighter colours to produce the pattern on the image.
I think this paper was harder than quite a few past papers. Not sure if everything I just typed up was accurate, I have forgotten quite a bit of the paper. Also some of my worded answers aren't very good as I rushed them here. This paper took a little longer than some past papers, I think I finished first pass through in 35 minutes.