H2 Electromagnetism
1 (a) (i) From N pole to S pole. 1
(ii) No effect. 1
(iii) The wire moves 1
vertically/at right angles to the field. 1
(iv) The wire moves in the opposite direction. 1
(v) Wire moves faster/more force on wire. 1
(vi) No effect. 1
(b) (i) Using your left hand point first finger in the
direction of the magnetic field 1
point second finger in the direction of
the current. 1
The thumb points in the direction of
motion (force). 1
(ii) The wire moves upwards. 1
(iii) The force on the wire is upwards. 1
Total 12
2 (a) N pole to S pole/left to right. 1
(b) Field and wire are at right angles/90°. 1
(c) (i) Upwards. 1
(ii) Downwards. 1
(d) The coil rotates. 1
(e) The commutator and brushes allow current to
flow through the coil during rotation, 1
the commutator reverses the current every
half cycle, 1
so rotation continues in the same direction. 1
Total 8
Wednesday, September 27, 2006
Friday, September 22, 2006
Y13 Wave Equation
Wave equation answers
1 0.17 to 20m
2 200 kHz, 0.6 and 0.59m, 5 exp 14 Hz
3 F = 20/60, 3/2wavelength = 21m so w = 14m, v= 4.67 ms-1
4 339.9 ms-1, 0.6m
This homework is now closed
1 0.17 to 20m
2 200 kHz, 0.6 and 0.59m, 5 exp 14 Hz
3 F = 20/60, 3/2wavelength = 21m so w = 14m, v= 4.67 ms-1
4 339.9 ms-1, 0.6m
This homework is now closed
Monday, September 18, 2006
y10 Homework
Use this mark scheme to mark your work out of 20. Remeber Q4 on H2 was printed incorrectly so the mark scheme may be wrong for this question.
H1 Simple electric current
1 (a) (i) Positive. 1
(ii) Negative. 1
(b) Complete circuit. 1
Current/charge flow. 1
Energy transfer from battery to motor.
Total 5
2 (a) Electrons not stuck to any particular atom. 1
(b) From negative to positive. 1
(c) From positive to negative. 1
(d) The direction of conventional current flow is
from positive to negative (the direction of +ve
charge flow). 1
(e) (i) Lamp connected to cell in complete loop. 1
(ii) Long bar of cell symbol labelled ‘+ve’,
short bar labelled ‘–ve’. 1
(iii) Electron flow labelled from negative
to positive. 1
(iv) Conventional current labelled from positive
to negative. 1
Total 8
3 (a) (i) A charged particle (atom, molecule). 1
(ii) Positive. 1
(iii) Negative. 1
(b) (i) Electrodes and electrolyte connected to cell
in complete loop. 1
(ii) They move towards cathode
(accept negative electrode). 1
(iii) They move towards anode
(accept positive electrode). 1
(iv) Electrons. 1
Total 7
H2 Series and
parallel circuits
1 (a) A, B, C. 1
(b) C, F. 1
Total 2
2 (a) If one lamp stops working, the other lamp will
still work. 1
(b) If one lamp stops working, all the other lamps
stop working too. 1
(c) In parallel. 1
Total 3
3 (a, b, c) Circuit drawn correctly with lamps in parallel. 1
Switch A in the same branch as lamp A. 1
Switch B in the same branch as lamp B. 1
(d) Circuit drawn correctly with a simple switch
between the cell and the junction where
the wires branch. 1
Total 4
4
switch A off off off off
(on or off)
switch B off on off on
(on or off)
‘mains is connected’ on on on on
(on or off)
motor to turn drum off off on on
(on or off)
Heater off off off on
(on or off)
marks 1 1 1 1
Total 4
5 (a) (i) The lamp is brighter than normal. 1
(ii) The lamp is at normal brightness.
(b) (i) 3V. 1
(ii) 1.5V. 1
(c) Parallel. 1
Total 5
6 (a) Diagram showing two cells in parallel. 1
(b) Diagram shows floppy disk drive in parallel
with computer. 1
CD-ROM drive in parallel with computer. 1
Total 3
H1 Simple electric current
1 (a) (i) Positive. 1
(ii) Negative. 1
(b) Complete circuit. 1
Current/charge flow. 1
Energy transfer from battery to motor.
Total 5
2 (a) Electrons not stuck to any particular atom. 1
(b) From negative to positive. 1
(c) From positive to negative. 1
(d) The direction of conventional current flow is
from positive to negative (the direction of +ve
charge flow). 1
(e) (i) Lamp connected to cell in complete loop. 1
(ii) Long bar of cell symbol labelled ‘+ve’,
short bar labelled ‘–ve’. 1
(iii) Electron flow labelled from negative
to positive. 1
(iv) Conventional current labelled from positive
to negative. 1
Total 8
3 (a) (i) A charged particle (atom, molecule). 1
(ii) Positive. 1
(iii) Negative. 1
(b) (i) Electrodes and electrolyte connected to cell
in complete loop. 1
(ii) They move towards cathode
(accept negative electrode). 1
(iii) They move towards anode
(accept positive electrode). 1
(iv) Electrons. 1
Total 7
H2 Series and
parallel circuits
1 (a) A, B, C. 1
(b) C, F. 1
Total 2
2 (a) If one lamp stops working, the other lamp will
still work. 1
(b) If one lamp stops working, all the other lamps
stop working too. 1
(c) In parallel. 1
Total 3
3 (a, b, c) Circuit drawn correctly with lamps in parallel. 1
Switch A in the same branch as lamp A. 1
Switch B in the same branch as lamp B. 1
(d) Circuit drawn correctly with a simple switch
between the cell and the junction where
the wires branch. 1
Total 4
4
switch A off off off off
(on or off)
switch B off on off on
(on or off)
‘mains is connected’ on on on on
(on or off)
motor to turn drum off off on on
(on or off)
Heater off off off on
(on or off)
marks 1 1 1 1
Total 4
5 (a) (i) The lamp is brighter than normal. 1
(ii) The lamp is at normal brightness.
(b) (i) 3V. 1
(ii) 1.5V. 1
(c) Parallel. 1
Total 5
6 (a) Diagram showing two cells in parallel. 1
(b) Diagram shows floppy disk drive in parallel
with computer. 1
CD-ROM drive in parallel with computer. 1
Total 3
Monday, September 11, 2006
Y11 boron
H1 Magnets
1 (a) Attracts. 1
(b) No effect. 1
(c) Repels. 1
(d) Attracts. 1
Total 4
2 (a) Diagram should have correct ‘butterfly’ shape
with lines starting and ending on the poles and
not crossing each other. 1
(b) The lines are close together where the field
is strongest. 1
(c) (i) Arrows pointing along lines from N pole
to S pole. 1
(ii) The direction is the one along which a
compass needle points, 1
or the direction in which an isolated
N pole would move. 1
Total 4
3 Magnetic field lines between the magnets parallel
and evenly spaced. 1
Arrows point from N pole to S pole. 1
Total 2
4 (a) (i) Opposite geographic north pole. 1
(ii) Opposite magnetic north pole. 1
(b) Towards Earth’s north pole. 1
(c) (i) Bar magnet drawn inside Earth along line
joining magnetic north and south poles. 1
Field lines should have same shape as
‘butterfly’ pattern of on magnet. 1
Arrows should point from bar magnet’s N pole
(Earth’s magnetic south pole) to the bar
magnet’s S pole. 1
(ii) N pole of bar magnet near to Earth’s
south pole. 1
(iv) There is not a bar magnet inside Earth. 1
The centre of earth is very hot 1
and a magnet would melt/its magnetism
destroyed by heat. 1
Total 10
1 (a) Attracts. 1
(b) No effect. 1
(c) Repels. 1
(d) Attracts. 1
Total 4
2 (a) Diagram should have correct ‘butterfly’ shape
with lines starting and ending on the poles and
not crossing each other. 1
(b) The lines are close together where the field
is strongest. 1
(c) (i) Arrows pointing along lines from N pole
to S pole. 1
(ii) The direction is the one along which a
compass needle points, 1
or the direction in which an isolated
N pole would move. 1
Total 4
3 Magnetic field lines between the magnets parallel
and evenly spaced. 1
Arrows point from N pole to S pole. 1
Total 2
4 (a) (i) Opposite geographic north pole. 1
(ii) Opposite magnetic north pole. 1
(b) Towards Earth’s north pole. 1
(c) (i) Bar magnet drawn inside Earth along line
joining magnetic north and south poles. 1
Field lines should have same shape as
‘butterfly’ pattern of on magnet. 1
Arrows should point from bar magnet’s N pole
(Earth’s magnetic south pole) to the bar
magnet’s S pole. 1
(ii) N pole of bar magnet near to Earth’s
south pole. 1
(iv) There is not a bar magnet inside Earth. 1
The centre of earth is very hot 1
and a magnet would melt/its magnetism
destroyed by heat. 1
Total 10
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