Marking Scheme
PHYSICS SEC MAY 2009 – MARKING SCHEME – PAPER IIB
1
(a) (i)
(ii)
(iii)
(iv)
(v)
Answers
extension, directly, force, elastic
A - spring
B - stand / clamp
C - pointer / indicator /nail / needle / marker
D - masses / load / weights
vertical ruler
Force / weight
mm / cm / m
Extension/mm
Marks
1,1,1,1
1
1
1
1
1
1
1
labelling of 1
axes
straight line 1
through the
origin
Comments
if students swap axes,
it is still correct
Force/N
(b) (i)
(ii)
(iii)
(iv)
(v)
2
(a) (i)
(ii)
(iii)
20.5 - 18 = 2.5 cm
10 cm
10 + 18 = 28 cm
the elastic limit of the spring has been exceeded /
extension is no longer proportional to the force
applied
less extension for the same force
otherwise when a large force acts on the sofa it will
produce too large a compression
spring will be permanently deformed (loose its
shape)
Total
A
90 - 55 = 35o
1
1
1
1
1
1
1
20 marks
1
1
N
Normal draw as shown
(iv)
(v)
total internal reflection
angle of incidence = angle of reflection / io = ro / the
same
(b) (i,
ii)
1
1
1
if no arrows are
drawn, remove 1
mark
F
correct ‘F’ marked
correct ray diagram
correct image
1
1
1
1
If diagram is not to
scale, give 0 marks.
Marking Scheme
(iii)
(iv)
(c) (i)
(ii)
Answers
inverted, real
magnification = v/u or hi/ho
= 1.3 ± 0.1 0.3
convex lens / converging
Marks
1,1
1
1
1
inverted, diminished
(d)
3
(a) (i)
(ii)
(iii)
(iv)
(v)
(b)
(c) (i)
(ii)
(iii)
(iv)
(v)
1,1
The apparatus shown was set up
1
The thickness of the lens and the distance
from lens to card were measured
3
A table of results was tabulated
5
Five different lenses were used and each
time the measurements were taken
4
A graph was plotted of lens thickness
against focal length
6
A sharp image of the object was obtained by
moving the card forward and backward.
2
5
Total 20 marks
1
Same as the velocity of the train
same speed / speed does not change / zero
acceleration
the passengers keep on moving
due to Newton’s 1st Law / inertia, an object which is
moving at constant speed keeps on moving unless an
external force acts on it
v = u + at
= 0 + (0.49 x 20)
= 9.8 m/s
F=ma
= 890 x 0.49
= 436.1 N
the two forces are equal
and opposite
Momentum = m1v1
= 0.075 x 0.05
= 0.00375 kgm/s or Ns
Momentum = m2v2
= 0.1 x 0.08
= 0.008 kgm/s or Ns
Total momentum = 0.008 - 0.00375
= 0.00425 kgm/s or Ns
the same 0.00425 kgm/s or Ns
Total momentum = (m1 + m2) v3
0.00425 = (0.075 + 0.1) v3
0.024 m/s = v in direction of larger train
Total
2
1
1
1
1
1
1
1
1
1
1
1+1
(units)
1
1
1
1
1
1
1
20 marks
Comments
lateral inversion
occurs also in lenses
5 all corr. 3 one pair
mixed up , if 5 & 6
only are correct then
1 mark
else 0 marks
Marking Scheme
4
Answers
Marks
correct shape of field lines
arrows in A, B, C and D
follow direction of field
lines
The direction of the N pole of magnetic compass
gives the direction of the field lines
1
like poles (N and N / S and S)
unlike poles (N and S)
in both cases the metal paper clips are attracted to the
magnet
the metal paper clips are unmagnetised but made of
magnetic material
so they attract to the bar magnet
magnetised
iron / nickel / cobalt
Permanent
time
steel
the bar magnet turns / rotates
an induced emf is produced in the coil wire
the bicycle lamp is on
mechanical energy to electrical energy / to light
increase no of turns of wire in coil / increase speed
of bicycle /stronger bar magnet /more magnets
Total
1
1
Comments
(a) (i)
(ii)
1
1
(b) (i)
(ii)
(iii)
(iv)
(c)(i)
(ii)
(iii)
3
any reference to
charges is marked as
0
1
1
1
1
1
1
1
1
1
1
1
1,1
1,1
20 marks
any two
Marking Scheme
5
Answers
Marks
bulb/copper wire
rheostat
ammeter and voltmeter connected correctly
overall circuit (complete circuit)
ammeter
rheostat / variable resistor
repeated
current
1
1
1
1
1
1
1
1
Comments
(a) (i)
(ii)
(iii)
(iv)
(v)
(b) (i)
(ii)
(iii)
(iv)
(v)
The graph for the
filament lamp may
have its initial stages
as a straight line and
then it is curved
directly
ohmic
not
non-ohmic
switch off circuit when not taking readings / read
ammeter & voltmeter from the front (no parallax) /
no loose connections - any one Do not accept
‘repeated readings’
a flow of electrons / charge
as current increases, resistance decreases
as temperature increase, resistance decreases
Non-ohmic
4
1,1
1
1
1
1
1
1
1
1
1
1
Total 20 marks