Download 1. (i) iron 1 for 1 mark (ii) 20 2 gains 2 marks else working gains 1

1.
(i)
iron
1
for 1 mark
(ii)
20
2
gains 2 marks
else working
gains 1 mark
(iii)
reverse input/output
1
for 1 mark
or increase secondary turns
[4]
2.
(a)
(i)
(pointer) moves to the left
1
accept (pointer) moves in the opposite direction goes negative
(ii)
a voltage / potential difference is produced between the ends of the wire
1
accept an induced voltage / current
(b)
any two from:

rotate (move) the wire coil faster

increase the strength of the
magnetic field
2
accept stronger magnets / move magnets together
bigger magnet is neutral

increase the number of turns (on the coil)

increase the area of the coil
larger coil is neutral

coils closer together
[4]
3.
ideas
rotation  electricity  generator
electricity  rotation  motor
reference to electricity supplied/produced via A&B
to armature rotating/being rotated
each for 1 mark
[4]
The Crypt School
1
4.
(a)
(i)
step-down (transformer) because fewer turns on the
output/secondary (coil)
1
no credit for just ‘step-down transformer’
accept ‘…less turns…’
do not credit ‘…fewer coils…’
or
‘the p.d. across the input / primary will be greater than the p.d.
across the output / secondary’
(ii)
to prevent a short (circuit)(through the turns of wire
or through the core
1
do not credit references to safety or heat (insulation)
(iii)
(easily) magnetised (and demagnetised)
1
accept ‘(it’s) magnetic’
do not accept ‘because it’s a conductor’
(b)
2250
2
correct substitution
150
500
eg

p.d.across secondary 7500
gains 1 mark
or
appropriate transformation
number of turns on secondary
number of turns on primary
× p.d. across primary gains 1 mark
eg (p.d. across secondary =)
(c)
any two from:
•
2
to reduce the voltage / p.d. (of the domestic supply)
or to reduce to 230 V
allow ‘to reduce to 240 V’
do not credit ‘reduce current to 230V’
•
higher voltage difficult to insulate
•
higher voltage (would) result in (fatal) electric shock
not just ‘less dangerous’
•
domestic appliances are not designed for (very) high
voltage (input) / (are designed) for 230V
do not credit ‘to increase efficiency’ / ‘to save energy’ do not
credit just ‘it’s safer’
The Crypt School
2
(d)
any two (1) each
•
if the (local) power station breaks down / fails / demand /
load exceeds supply
1
1
or words to that effect
•
electricity / power can be switched from elsewhere in the
system / from other power station(s)
or words to that effect
•
electricity can be generated in places remote from customers
or words to that effect
•
(in total) fewer power stations are needed
•
power available in rural / remote areas
•
National Grid allows for (better) control of supply and demand
do not credit just cheaper / more efficient / safer
[9]
5.
Quality of written communication:
1 mark for correct sequencing
1
magnet in produces voltage / current
→ magnet out produces voltage /
current → in opposite direction
any three from:
3
magnet moved to coil / coil
moved to magnet
produces a current / voltage
correct reference to induction
magnet moved from coil / coil moved from magnet
produces current / voltage
correct reference to reversal of current / voltage
[4]
6.
each mark may be gained from a written description or from a
caption on the diagram or from both together but do not credit
if there is any contradiction between them
one coil on each side
1
of insulated wire
1
or insulated coil
number of turns on primary coil/
The Crypt School
1
3
coil 1/input coil greater than number of
turns on the secondary coil/
coil 2/output coil
this must be clear for example do not credit more coils do not
credit bigger coil
core of laminated iron
1
or core of (soft) iron
[4]
7.
(a)
(magnetic) field / lines of force / flux rotate(s) / move(s) / through /
in / cut(s) the coil
1
do not credit the idea that movement ‘creates’ the magnetic
field
potential difference / p.d. / voltage induced across the coil
1
do not credit just ‘current induced’
(b)
any one from:
•
more powerful / stronger / lighter magnet
•
larger / more / bigger / lighter cups / with a bigger surface area
•
longer arms
•
lubricate the spindle
•
add more turns to the coil / nail
1
do not credit ‘a bigger magnet’
[3]
8.
(a)
(i)
the ammeter needle will deflect/will register a reading/will
move from zero position
2
the deflection of the ammeter reading will be repeatedly to and fro/
will keep changing direction
for 1 mark each
(ii)
the moving coil of wire cuts through/across the magnetic
field/flux/lines of force
2
the direction of movement of the opposite sides of the
coil reverses every half cycle/revolution
for 1 mark each
The Crypt School
4
(b)
twice the frequency/half the wavelength
(i.e. two and half cycles shown)
3
for 2 marks
else greater frequency/more cycles/shorter “wavelength”
for 1 mark
greater amplitude/height
for 1 mark
[7]
9.
(a)
any three of the following:
 use a coil with more turns or increase loops of wire or more coils
use a stronger magnetic field or magnet or magnets closer together
wind coil onto an iron core
rotate coil faster
reduce resistance of the coil or bulb or circuit or use thicker wire or increase
conductivity
increase the area of the coil or size of coil
3
(b)
current creates an electromagnet or magnetic field
1
electromagnet or magnetic field rotates or moves
1
field links with (stationary) coil or induction or cutting of field lines
1
[6]
10.
(i)
away from magnet
1
arrow should be perpendicular to field lines and current as
judged by eye
(ii)
current in wire creates magnetic field around wire
1
two fields interact or combine giving a resultant force (on the wire)
1
[3]
The Crypt School
5