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WorksheetsCity and Guilds 8202 L2 Scientific Principles
Total questions: 17
Worksheet time: 9mins
The SI system of measurement is split into two groups; base units and derived units. what is meant by the term derived units?
Combination of the five base units by a system of addition and subtraction calculations.
Combination of the seven base units by a system of addition and subtraction calculations.
Combination of the five base units by a system of multiplication and division calculations.
Combination of the seven base units by a system of multiplication and division calculations.
How do we calculate an area?
length x width
length x width x height
length x width x height x 1000
Force(mass (kg) x acceleration (m/s2))
What is the equivalent metric pipe diameter to imperial 1"?
15mm
22mm
28mm
35mm
What is meant by the term 'relative density'?
Relative density is the ratio of the density of a substance to the density of a standard substance under specific conditions.
Comparison of different substances to each other
Comparison to other substances at -273.15 oC (0oK)
Comparison of substances to sea water at sea level.
Pure metals are derived directly from the ore and contain small amounts of impurities. What are these metals?
Steel, stainless steel, brass, gunmetal, pewter.
iron, copper, aluminium, lead, zinc, tin
cast iron, pig iron, wrought iron, low carbon steel.
tool steel, spun iron, low carbon steel
What are the five main types of plastic used in the plumbing industry?
Bakelite, polyester, nylon, polythene, rayon
uPVC, polyethylene, polypropylene, polybutylene, ABS
mdpe, hdpe, polyester, nylon, polypropylene
uPVC, mdpe, nylon, polythene, rayon
The Mohs hardness scale lists materials in a range of hardness 1-10, which material is at 1 on the scale and which one is at 10?
gypsum and titanium
feldspar and quartz
corundum and calcite
talc and diamond
Dezincification is a type of corrosion that happens to what material?
Copper
Zinc
Tin
Brass
Erosion corrosion occurs in tubes and fittings due to the effect of fast flowing fluids and gases. What can accelerate this type of corrosion?
Poor workmanship, ends not cut square or deburred, excess solder.
Use of leaded solder and acid flux
excess PTFE tape in threaded joints
lack of pipe sealant and corrosion inhibitor
For galvanic corrosion to occur, three conditions must be present, these are?
electrochemically similar metals must be present, these metals must be in electrical contact, these metals must be exposed to an electrolyte
electrochemically similar metals must be present, these metals must not be in electrical contact, these metals must not be exposed to an electrolyte
electrochemically dissimilar metals must be present, these metals must be in electrical contact, these metals must be exposed to an electrolyte
electrochemically disssimilar metals must be present, these metals must not be in electrical contact, these metals must not be exposed to an electrolyte
Degradation of plastics can occur from a variety of causes. These are?
heat, light, gases, water
heat, light, oxygen, infra red
heat, light, hydrogen, ultra violet
heat, light, oxygen, ultra violet
What is the boiling point of water at sea level?
80oC
100oC
90oC
98.8oC
We can protect steel or iron by galvanising. What is galvanising?
Painting with a bitumastic paint
coating with a thin layer of chromium
wrapping with Denso tape
coating with a thin layer of zinc.
Wet central heating systems can be protected from corrosion by the use of which substance mixed with the water?
Calcium carbonate
Sulphur dioxide
Corrosion inhibitors
Iron oxide
Sacrificial anodes are placed inside hot water storage cylinders to protect them from which type of corrosion?
Rusting
Acid
Electrolytic
Erosion corrosion
How are plastics protected from the effects of UV light.
Painting
Wrapping
Sleeving
Galvanising
What is meant by the term anodising?
Coating one metal with a layer of paint
Coating one metal with another by electrolysis to form a protective barrier against corrosion
Coating one metal with a layer of Denso tape
Coating one metal with grease or oil
