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A.C.
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abbreviation for
alternating current
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| Abrasive |
a
material which smoothes and removes marks from wood, plastics and metal;
see sand paper or glass
paper |
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Absorbency |
The ability to
absorb liquid. |
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| Acetate
sheet |
a
thin transparent plastic usually colourless but also available in coloured
form; a useful material when transparency is needed e.g. in making a
torch, or windows in a model of a building. Can be vacuum formed for
'bubble packaging'. |
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| Acrylic |
a
thermoplastic often referred to as PMMA (polymethyl methylacrylate) but
commonly known as Perspex. |
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| Actuator |
a device which
operates something |
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Additives |
Synthetic or
natural chemicals used in food production to colour, preserve or enhance
flavour. Food additives approved by the EU have an E number. |
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| Adhesive |
a
substance used to stick materials together; examples include PVA
glue, cow gum, low temperature hot melt glue |
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| Advertisement |
information
about a product or service used to attract potential consumers;
advertising takes place in newspapers and magazines, on hoardings, on
radio and television and on the Internet |
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Aeration |
Lightening
materials or ingredients by incorporating air. |
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| Aesthetics |
the area
of design concerned with making products look attractive |
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| Allergy |
unusual
sensitivity to the action of food, pollens, insect bites etc. You should
find out about any allergies your pupils may have to foods or materials
before using them in the classroom. You should get parental approval for
activities that involve tasting. |
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| Alloy |
a combination of
two or more metals or a metal and another element to produce a metal with
different characteristics. |
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| Alternating
current |
electric current
which changes direction from +ve to -ve at a set frequency |
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| Ampere |
This is the unit of
electrical current, often shortened to Amp. It is given the symbol '
I ' in calculations and
can be found by dividing volts with ohms. |
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| Amplifier |
a circuit
that makes small signals bigger |
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| Amplitude |
the height or
size of a signal |
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| Analogue
Signal |
a signal with a
changing amplitude |
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| Analysis |
investigating
something to find out about it |
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| Anode |
This is the positive
electrode in a circuit. It is commonly linked with diodes
and thyristors. It is the opposite of cathode. |
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| Annealing |
This is a method which
is used to make metal softer and easier to work by reheating . By re-heating the metal the crystal lattice can reform, reversing
the effects of work hardening
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| Annotation |
brief
notes added to design sketches to make things clearer or to give more
detail |
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Anthropometrics |
The study of the
measurement of human beings and their movements. |
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| Appearance |
the
way something looks to an observer |
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| Artefact |
a
manufactured object |
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| Assembly |
the
way parts of a product are fitted together |
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| Assessment |
a
judgement of your achievement |
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Astable |
An electronic
system where the output continuously switches on and off (often called a
pulse generator). |
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| Automata |
model figures
which use mechanisms to create
movement |
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| Axis |
the centre of rotation |
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| Axle |
the
shaft on which wheels are carried. The wheels are either
fixed so that they turn with the axle or able to spin freely on the axle. |
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