Unit 2 (Energy Generation, Energy Storage, Modern Material, Smart Materials, Systems Approach to Designing, Electronic Systems, Mechanical Systems)

Question 1

How do solar panels work

Answer 1

They are made of photovoltaic cells
Photons hit them
Allows electrons to flow
Creates electrical current

Question 2

How do wind turbines work

Answer 2

Blades move, which turns a generator

Question 3

How does tidal electricity work

Answer 3

Tide passes through tidal barrage
Turns a generator
Makes electricity

Question 4

Define pneumatics

Answer 4

Accurate and low maintenance
Compressed air or gas to create movement
Use in industry: drills and automated production lines

Question 5

Define hydraulics

Answer 5

Pumped and compressed liquid is used
More powerful than pneumatics
Uses in lifting equipment and car braking systems

Question 6

Define kinetic pumped storage

Answer 6

Tops up the National Grid power supply at peak times when more electricity is needed. A kinetic-pumped storage system works by having two reservoirs and a hydroelectric dam system.
During night, water pumped up to higher reservoir when energy is low, however as energy is needed during the day, water turns a turbine as it flows back down through the dam

Question 7

Define flywheel energy storage

Answer 7

Flywheels that rotate in a near frictionless environment
Use surplus energy
Momentum is stored

Question 8

Define chemical energy storage

Answer 8

Batteries
Canisters
Hydrogen fuel cells

Question 9

What are the types of battery

Answer 9

Alkaline: efficient and high capacity, household use
Rechargeable: used in portable domestic appliances, electric cars and disability/personal transport
Emerging battery technology: large units to smooth demands on National Grid, fast charging
Disposable: toxic when disposed

Question 10

What are the types of potential energy (stored)

Answer 10

Mechanical
Chemical
Nuclear
Gravitational

Question 11

what are the types of kinetic energy (motion)

Answer 11

Electricity
Movement
Heat
Sound
Light

Question 12

Define modern material

Answer 12

New and improved material that helps solve design and environmental issues, and technical constraints

Question 13

Examples of modern material

Answer 13

Biodegradable polymers: vegetable starches|use in packaging
Flexible MDF: creation of natural curves|use in shop fittings
Poly/coolmorph: biodegradable, non toxic and can be coloured|use in modelling
Titanium: can be alloyed, non-corrosive, lightweight, tough, stiff, non-dense|medical appliances
Fibre optics: flexible, glass core|endoscopes
Graphene: flexible, thin, conducts| electronics and energy storage
Liquid crystal display (LCD): monochrome and colour|thermometers and watches

Question 14

Define smart material

Answer 14

Materials that undergo a change when exposed to a stimuli

Question 15

Examples of smart material

Answer 15

Self healing polymer: microcapsules of resin fill stress cracks|construction materials
Self healing concrete: spheres of bacteria added to mixture which create there own food, so when crack forms and water enters, they produce calcium carbonate to fill the crack|geothermal energy plants (marine)
Thermochromic pigment: temperatures trigger a change in colour|room thermometers
Photochromic particles: ultraviolet light reacts with photosensitive silver|proscriptive glasses
Shape memory alloy: ‘sets’ in shape with heat and always returns to it
Quantum tunnelling composite: flexible polymer with metal particles, pressures allows it to conduct|speed controllers
Piezoelectric transducer: detect frequencies when crystals in the transducer deform (compression or stretching)|microphones

Question 16

Steps for making a moulded piece of glass/carbon reinforced plastic (G/CRP)

Answer 16

1) prepare mould
2) apply release agent
3) apply first resin or gel coat for G/CRP
4) add the desired matting
5) work second resin coat
6) repeat leaders of matting and resin coat
7) clamp and leave to cure
8) trim or finish

Question 17

Types of composite materials and technical textiles

Answer 17

Gore-Tex: waterproof but breathable|coats
Aramids: high strength, flame proof|military applications
Conductive fabrics and thread: are stainless steel conductive strands|communication
Microfibres: electrostatic charges that collect dust|cleaning cloths

Question 18

Define input

Answer 18

A real world signal such as light, sound or movement that turns into an electrical signal

Question 19

Define process

Answer 19

Receives input stage and adds functionality and intelligence

Question 20

Define output

Answer 20

Takes the process and turns it into a result

Question 21

Define integrated circuits (IC)

Answer 21

Also known as microchips, they perform specific tasks. The programmable versions are called microcontrollers

Question 22

Define peripheral interface controller (PIC)

Answer 22

A microcontroller that can provide functions controlled by a downloading cable. They are reprogrammed many times

Question 23

Define monostable device

Answer 23

A device that turns on but then off to a stable state

Question 24

Define astable device

Answer 24

A device that is unstable and switches on and off repeatedly

Question 25

Define digital

Answer 25

Either on or off, can be presented as 0 or 1

Question 26

Define analogue

Answer 26

Has an infinite range of values between a minimum and maximum mark. They input divide signals into 256 equal parts

Question 27

First class lever

Answer 27

Example is a see-saw

Load________fulcrum________effort
∆

Question 28

Second class lever

Answer 28

Example is a wheelbarrow

Effort_________load________fulcrum
∆

Question 29

Third class lever

Answer 29

An example is a fishing rod

Load___________effort___________fulcrum
∆

Question 30

How to calculate force from a pulley system

Answer 30

Systems that use multiple pulleys are called block and tackle systems

Force (N) = 1/amount of pulleys

Question 31

Define idler gears

Answer 31

Gears placed between two outer gears to ensure the two are moving the same direction

Question 32

How does nuclear power work

Answer 32

Uranium is split in a fission reaction, releasing lots of energy