Question(1)
Scenario: Scientists want to do the experiment on thermal conductivity of the different materials. (Thermal
conductivity is basically talking about the temperature sustainability of the
material when it have been heating up for certain periods of time. A box, which
is shown in this picture represents a house and different pieces of material are
heat up with Quartz halogen light, which is a light powerful light bulb. If the
temperature do not really change, the material has high resistance to heat and
row sustainability.) They prepared six distinguished materials which are
Aluminum, steel, acrylic, polystyrene, plywood, and pine. They are going to use
different kinds of data logger to record and analysis the data.
(This picture is taken by a Design Technology student who did the same experiment as the scenario)
(which is me. I did this experiment in my DT class last year... therefore no citation!)
Exam Questions
(a) Define the term real time data collection. (2)
(b) Identify one analogue output device and one digital out put device involved in data logging. (2)
(c) Explain advantages and disadvantages of the real time data collection. (6)
(d) Evaluate the analogue device as compared to digital devices. And discuss how they are suitable or not
suitable for the scenario. (10)
(a) Define the term real time data collection. (2)
Real-time data collection means the information that is delivered immediately after the collection.
There is no delay in the timeliness of the information provided.
(b) Identify one analogue output device and one digital out put device involved in data logging. (2)
Analogue: thermometer, voltage logger
Digital: sound wave meter, heat meter
(c) Explain advantages and disadvantages of the real time data collection. (6)
Advantage:
 The information is always up-to date
 Easier to see the changes in the results
Disadvantage:
 It will not be really suitable for long term data logging
 Impossible to see the final result - which means people need to wait until the result comes out
(d) Evaluate the analogue device as compared to digital devices. And discuss how they are suitable or not
suitable for the scenario. (10)
Analogue
 Analogue device can be not really accurate
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Need human workers to record and analysis the data
Suitable for short term experiment
Anyone is accessible and able to purchase because it is cheaper
It is not suitable for scenario because there are a lot of things to measure
Taking too much time
Human errors
Digital
 It atomically records and analysis the data
 Machine sometimes can be expensive
 Needs a lot of equipments (software, hardware and PC to record the data)
 Less time consuming
 Too much information (e.g, machine can record the temperature per second... and if it is the long
term experiment...)
Question(2)
A young kid Alexei loves to watch cable TV programs. Although the cable TV
is quite old, it 'was' enough to watch channel programs. But one day, rainy
season has come and the cable of Alexei's house is heavily damaged due to
flood. Therefore, Alexei was not able to watch cable TV anymore. Therefore,
Alexei's family searches for the new way of connection As a result, they
finally find out the method called 'satellite communication'.
Q1. Define the term of satellite communication. (2 marks)
Q2. Explain ONE advantage and ONE disadvantage of satellite Communications. (4 marks)
Q3. Describe the process of how signals can bring to Alexei's house. (4 marks)
Q4. Alexei's family now understood the advantage of the satellite communication and started to use it as their
main connection side then. However, there are some disadvantages as well. Base on advantage & disadvantage
that you have written in Q2, write a short paragraph about to what extent did satellite communication have
changed people's lives and how did it impact on the environment. (10 marks)
Mark Scheme
Q1. (Total 2 marks)
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A satellite that has been stationed in space for the purpose of providing
telecommunications;
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Commonly used for mobile phone signals, weather tracking, or broadcasting
television programs;
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Artificial satellites that relay receive signals from an earth station and then retransmit
the signal to other earth stations. They commonly move in a geostationary orbit.
Q2. (Total 4 marks)
Advantages:
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used for long distance communication
high speed data transmission
many receiver stations can receive signal from the same sender station
Flexible (if transparent transponders)
Easy to install new circuits
Circuit costs independent of distance
Broadcast possibilities
Temporary applications (restoration)
Niche applications
Mobile applications (especially "fill-in")
Terrestrial network "by-pass"
Provision of service to remote or underdeveloped areas
User has control over own network
1-for-N multipoint standby possibilities
Disadvantages:
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Large up front capital costs (space segment and launch)
Terrestrial break even distance expanding (now approx. size of Europe)
Interference and propagation
Congestion of frequencies and orbit
Q3. (Total 4 marks)
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The satellites that aid the transmission of television signals have elliptical or
geostationary orbits;
The satellite television setup consists of a transmitting antenna or uplink satellite
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dishes pointed towards specific satellites;
The satellite houses transponders, which receive signals from the antenna;
The uplinked signals are tuned to a frequency range that corresponds to that of the
transponders;
The transponders retransmit the signals back to Earth;
The signals that are transmitted by the transponders on a satellite are received by the
parabolic dish;
The signal is reflected towards the feed horn, a device mounted at the focal point of
the dish;
The satellite receiver sends the signals to the television set.
Q4. (Total 10 marks)
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Artificial satellite has limited functioning period which will crash on earth or remain
around the orbit someday.
Most dust around the earth orbits are wreck of artificial satellites;
The satellite communication brought global communications
The satellite communication brought satellite mapping
The satellite communication has brought the invention of GPS/Navigation
It helped on astrogeology to observe part of the universe.
Question(3)
Computer factories are making more and more PCs every year. The number
of PC shipments for import and export exceeded
9 billion last year. Some of the materials the factories use for making PCs
are silicon, copper, plastic, fossil fuels, and chemical.
Fossil fuels used in making PCs include oil and natural gas. These materials
are non-renewable. The amount of fossil fuel
started to decrease dramatically from 2002 and is predicted to decrease
more in the future.
1. Define the term resource depletion. (2 marks)
2. Discuss two causes of resource depletion. (4 marks)
3. Examine two impacts of resource depletion as it applies to computer industry. (4 marks)
4. To what extent does the increased use of mobile computing outweigh the concerns of resource depletion and
ewaste?
1.
Define the term resource depletion. (2 marks)
Use of renewable resources and non-renewable resources beyond their rate of replacement within a region
2. Discuss two causes of resource depletion. (4 marks)
-Irrigation (1)
Irrigation needs water. Lots of irrigation needs lots of water. Over use of water can cause resource depletion of
water. (1)
-Over population (1)
More amounts of resources are needed in order to manage the large number of people. (1)
-Mining for oils and minerals (1)
Minerals and oils are needed to provide humans with food, clothing, and housing and to continually upgrade the
standard of living. Some minerals are renewable and some are not. (1)
-Technological and industrial development (1)
As the technology is developing, more and more resources are needed to fulfill the needs. For example, fossil
fuels are needed more now because more computers are being developed than before. (1)
3. Examine two negative impacts of resource depletion as it applies to computer industry. (4 marks)
The resources available for the computer industry to use are coming short. Fossil fuels are likely to be extinct in
20 years. Without fossil fuels, computers cannot be made. Because of the scarcity of some resources, the
computer industry will not be able to produce many computers in demand. The price of the computer will
eventually rise. The company’s sale will decrease.
Resource depletion can cause increase in unemployment rate. Once no more computers can be made, due to
the resource depletion, the computer industry may go bankrupt. People who used to work in the computer
industry could become unemployed. They would have to find a new job.
4. To what extent does the increased use of mobile computing outweigh the concerns of resource
depletion and e-waste? (10 marks)
Mobile computers have made people’s lives a lot convenient.
-Mobile computers are portable.
-You can take it anywhere
-People can get online anywhere with wireless Internet connection with just with laptops.
-Mobile computers are light so people can carry easily.
-People can work with motion using mobile computers. Don’t have to sit in particular place in a position.
However, there are disadvantages to using mobile computers.
-Mobile computers worn out more easily than desktop computers.
-Batteries start to last shorter in about a year.
-Takes longer time to boot, as it gets old.
-People are more likely to change laptop instead of recycling and replacing the pieces.
-This causes resource depletion since computer manufacturers have to make more computers for customer’s
demand.
-This also leads to e-waste because most of the worn out computers just get thrown away, without being
recycled.
-Thus, increase in use of mobile computers, such as laptops and smart phones, can be harmful for resource
depletion.
Question(4)
Environment
question is about satellite communication (20Marks)
A lonely boy Shawn has relied on broadband internet connection to
Skype with his girlfriend, however in recent years broadband
connection has become overly crowded and Shawn's Skype signal
his girlfriend started lagging. He decided to pay for internet satellite
services, Shawn believed and expected satellite internet
This
with
connection to be faster, more stable, and private.
1. Define Satellite Communication (2 marks):
2. Describe two social and ethical issues involved in using Satellite Internet connection for private internet
connection (4 marks):
3. Explain two reasons why Satellite communication can benefit the communications industry (4 marks):
4. Shawn has relied on internet satellite services ever since, however Shawn had to pay an additional 100 us
dollars for the internet satellite service. In a short paragraph write a summary about: to what extent has Satellite
communication changed our lives? And how has this impacted our environment? (10 marks)