1. (a) arrow
drawn to the left; 1
(b) the sizes are equal; 1
(c) the strips have the same type of charge;
similar charges repel 2
similar charges repel 2
(d) (i) electrons ; 1
(ii) positive, there are more positive charges
than negative 1
[6]
2. by
movement of electrons/negative charge; 2
from earth/switch to the man;
Reject positive electrons (for both marks)
from earth/switch to the man;
Reject positive electrons (for both marks)
[2]
3. any 2 from:
causal mechanism
causal mechanism
Accept
e.g.
(due to) friction/rubbing
(due to) friction/rubbing
Ignore
repeat of stem
what moves
Accept
negative charge moves OR electrons
which direction;; 2
Accept
onto hose OR from fuel
Reject
incorrect physics
Reject
for the last two marking points ions or positive electrons
consequence
AND some explanation;
both
needed for the mark
e.g.
chance of explosion as fuel is flammable
chance of explosion/ignition if spark
e.g.
chance of explosion as fuel is flammable
chance of explosion/ignition if spark
Do
not award repeat of stem… ‘it is dangerous’
Ignore
(electric /static) shock
Reject
unqualified explosion
OR
explanation AND some consequence; 1
explanation AND some consequence; 1
Accept:
static build-up/it could ignite fuel
static build-up/it could cause explosion
spark/it could ignite fuel
static build-up/it could ignite fuel
static build-up/it could cause explosion
spark/it could ignite fuel
movement of charge (in wire);
Accept:
electrons/charges move (along the wire)
electrons/charges move (from hose to plane)
electrons/charges move (along the wire)
electrons/charges move (from hose to plane)
Reject
ions or positive electrons for the first mark
UNLESS mark has been deducted in a
UNLESS mark has been deducted in a
effect of this movement; 2
Accept:
this discharges it/the static build-up
this neutralises it
this earths it/to earth
this grounds it/to ground
gives plane and hose the same potential / same charge
this discharges it/the static build-up
this neutralises it
this earths it/to earth
this grounds it/to ground
gives plane and hose the same potential / same charge
Accept
this prevents a build up of charge for both marks
Ignore
floor
Mark
in either order
QWC
(1)
[6]
4) (a)
(i) friction between the beads and pipe
accept
beads rub against the pipe
1
(cause)
electrons to transfer
accept
electrons are lost/gained
do
not accept negatively charged atoms for electrons
3rd mark point only scores if 2nd mark
scores
1
from
the pipe
do
not accept from the (negatively) charged pipe
or
to the beads
to the beads
do
not accept to the (positively) charged beads
accept
negative charge transfer to the beads for 1 mark provided 2nd or 3rd marking point not awarded
mention
of positive charge transfer negates last 2 marking points
1
(ii) volume
of beads
accept
(75)cm3
or
length of pipe
length of pipe
accept
use the same pipe
or
or
speed the beads are poured
speed the beads are poured
poured
the same way is insufficient
or
angle of pipe
angle of pipe
1
(b) (i)
the larger the beads the less charge
do
not accept inversely proportional
negative
correlation is insufficient
1
(ii) (total)
charge decrease
results
would be lower/smaller would be insufficient
1
beads
in contact with pipe (walls) for less time
accept
less contact (between beads and pipe)
accept
beads in pipe for less time
or
smaller surface area (to rub against)
smaller surface area (to rub against)
accept
less pipe to rub against
less
friction is insufficient
1
(c) (i)
(pumping very) fine powders
reason only scores if (very) fine powders given greater
charge (build up)
accept
more static (electricity)
accept
an answer that correctly relates back to the experimental data
or
higher pd/voltage
or
greater energy
higher pd/voltage
or
greater energy
accept
larger surface area to volume (ratio)
1
(ii) idea
of earthing (the pipe)
accept
use metal pipes
do
not accept use larger particles
1
(d)
to compare (the relative risks)
fair
test is insufficient
you
can only have one
independent
variable is insufficient
or
different conditions change the MIE value
different conditions change the MIE value
accept
different conditions change the results
do
not accept avoid bias
1
(a)
(i) Ends have charge
Which is opposite on each rods
Which is opposite on each rods
(ii)
Attracts
(b)
(i) Repulsion
(ii)
Ends have same charge
(c)
Electrons move between cloth and rod
Where gather is negative
Where move from is positive
Where gather is negative
Where move from is positive
3
(6
marks)
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