2022 exam paper Flashcards
Outline two health benefits of using CO₂ monitors in classrooms
Creates awareness of air quality.
* Reduces the risk of Coronavirus transmission.
* Improved amounts of fresh air and oxygen circulating.
* Improved sleep quality.
* Increased cognitive function and boosts brain health.
* Boosts immune system.
* Reduces “sick building syndrome”, etc.
Describe, with examples, the difference between amorphous structures
and crystalline structures.
Amorphous Structures - these structures have
irregular and non-geometric patterns. e.g. Acrylic.
Crystalline Structures - these structures have
regular, geometric and repeating molecular
patterns e.g. BCC, FCC CPH.
Explain what is meant by 100:1 gear ratio motor
The 100:1 ratio on this motor indicates that the output shaft is rotating 100 times slower than the
input shaft. Therefore, if the input shaft is rotating at 2000rpm the output shaft is rotating at
20rpm.
Discuss the contribution that any one of the following has made to technology:
(i) Nikola Tesla
Nikola Tesla (1856 – 1943) was a Serbian-American engineer and physicist made dozens of
breakthroughs in the production, transmission and application of electric power.
He is best known for creating the first alternating current (AC) motor and developed AC
generation and transmission technology.
Explain two environmental benefits of using hydrogen
powered fuel cell vehicles in modern urban transportation.
The biggest advantage to a hydrogen-powered fuel cell vehicle is that it only produces water and
air, which are not harmful to the environment.
Driving hydrogen fuel-cell powered vehicles would eliminate greenhouse gases and help reduce air
pollution.
Does not require large areas of land to produce hydrogen
Explain the term allotropy in relation to iron.
Allotropy is the property of some chemical elements to exist in two or more different forms. Iron
exists as a BCC structure up to approximately 910°C. Between 910°C and approximately 1390°C it
exists as a FCC structure.
Describe two benefits of applying plastic powder coating to mild steel frames.
- Tougher, more durable coatings.
- Corrosion resistant.
- Consistent finish.
- No solvent disposal.
- Ease of application
- Quick process.
Outline one method of reducing or eliminating the impact of any harmful fumes that may
be created in the soldering of electronic circuits.
Ensure adequate ventilation in the work area.
Use fume extraction system.
Do not breathe in fumes from the plume of smoke created by resin flux heating.
A risk assessment of the process and measures should be undertaken.
Identify two reasons for the use of titanium in the manufacture
of sport equipment, such as in modern golf clubs, as shown.
Titanium is strong, long lasting and lightweight. Titanium is lighter than stainless steel and allows
the designer to manufacturer a much larger club head that meets the weight specifications of a
normal driver. Titanium does not corrode either.
Identify one advantage and one disadvantage of a gas shielded
welding technique over a flux shielded welding technique.
advantages:
No slag on the weld.
* Less toxic fumes produced.
disadvantages
Difficult to use outdoors.
* Cylinders need to be refilled.
Outline one advantage and one disadvantage of
solar farms in Ireland.
Advantages of solar farms
* Renewable energy source.
* Reduced electricity bills.
* Diverse applications.
* Low maintenance costs.
Disadvantages of solar farms
Weather dependent.
* Expensive to initially set-up.
* Use up lots of space.
* Solar energy is expensive to store.
Describe, with the aid of diagrams, the process
of dendritic growth.
Dendritic growth:
As a metal reaches its cooling point small particles cool first. Solidification takes place in a pattern.
This pattern is called Dendritic Growth and looks like the branches of a tree.
Each small particle grows to form a crystal or grain. Crystals grow together to form a solid.
This process is known as dendritic growth from Greek word “dendron” for treelike.
Describe, with the aid of a diagram, any two
crystal point defects which may occur during
the solidification process.
Substitute Defect
This is where foreign atoms replace the
parent atoms.
Vacancy Defect
This is where there is an atom missing
from the lattice.
Interstitial Defect
This is where foreign atoms fit in between
the parent atoms.
explain:
(i) The impact of a dislocation in crystal structures.
The impact of dislocation in crystal structures.
* Dislocations can move as far as grain boundaries under a shear stress. Fine grained
metals are stronger, stiffer and harder than coarse grained metals.
* Dislocations promote material malleability. The motion of dislocations allows slip
deformation to occur.
* Heat treatments can impact on dislocation density caused by cold working
explain
The possible corrosive effects of the environment
on metal objects.
The possible corrosive effects of the environment on metal objects.
* Ferrous metals (e.g. steel) may rust. This may cause early failure of steel products.
* An oxide layer can form on some metals such as aluminium giving a dull colour.
* Other metals may tarnish due to corrosion e,g. copper can turn a green colour.
* The presence of water (especially acidic water) can initiate electrochemical reactions
in some metals e.g. stainless steel or zinc are impacted by seawater.
