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Cambridge University Press 2011

Range and scope ofcomputer applications

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Cambridge IGCSE Computer Studies Answers to Revision questions: 7 Range & scope of computer applications 1

Below each answer there is a page reerence or the coursebook. Tis is there to help you ocus

your revision. I you nd that you get an answer wrong, you can use this guide to return to the

coursebook to revise the areas that need some extra attention. Please note these are example

answers only and do notrepresent the only possible answers.

1 a eachers could use the network to complete a computerised register and the senior

management staff could send emails to the other members o staff.

See Communication systems on page 150.

b Sofware applications that could be used are email clients, such as Outlook (see page 12) andweb browsers, such as Fireox (see page 14).

2 A microprocessor can monitor the patient 24 hours a day, 7 days a week without getting tired or

misreading data.

See Monitoring hospital patients on page 179.

3 A thermometer could be hung in the greenhouse and a humidity sensor could be stuck in the

soil. Both sensors could be connected to a computer to set up an input eedback system. Te

computer would run a program that would test the sensor readings at regular intervals. I a

reading ell outside the limits set in the sofware, the computer would then activate an actuator.

I the soil became too dry, an actuator could run a sprinkler system or a time. I the temperature

was too low, the actuator would close a window or start a heater.

See Monitoring and control systems on page 179 Sensors on pages 66, 67 and 70.

4 a Inputs used by the traffi c lights system include those rom sensors that tell i a vehicle is

approaching the lights (or junction) and input rom sensors that count the number o

vehicles passing the lights.

b A computerised traffi c lights system can be responsive to changing traffi c conditions

(unlike a timed system). It can also enable the traffi c department to test out changes to the

sequences o the lights.

See Monitoring and control of traffi c on page 184.

5 Robots are now used in many different situations.

a A robot could use pressure sensors and light sensors.

b A pressure sensor could be used to ensure that the robot is touching an item beore it carries

out another action. A light sensor could be used to enable the robot to navigate around a

workplace.

See Industrial robots on page 192 and Pressure sensors and Light sensors on page 68.

c Robots in actories can be used or welding, placing parts and moving objects around.

d Robots can work in places or doing jobs that would be dangerous or people. Robots can

work all day and night without breaks. Robots can accurately repeat a task many times.See Industrial robots on page 192.

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Cambridge University Press 2011Cambridge IGCSE Computer Studies Answers to Revision questions: 7 Range & scope of computer applications 2

6 a Instant messaging is a acility that enables users connected to the Internet to chat in real-

time. A school could use instant messaging to give pupils the opportunity to exchange

messages with pupils in other schools around the world.

See Communication systems on page 150 and Instant messaging on page 13.

A search engine is a web application that indexes web pages (in its databases) and enables

a user to run queries against the index. School pupils could use a search engine to nd

inormation or a project.See Search engines on page 206 and on page 15.

Favourites are a acility o a web browser that enables a user to save the address o a page so

that it can be accessed quickly. A school could provide its pupils with a set o avourites that

are or recommended websites.

See Web browsers on page 14.

A social network is a website that enables users to exchange messages, photographs

and other personal inormation. A school could have a social networking site to share

inormation about its students to other members o the student body.

See Social networking websites on page 232.

b I pupils have unsupervised access to the Internet, they may access inappropriatematerial or download malware. Access to inappropriate material can be reduced by using

parental control sofware to block certain sites. Anti-virus sofware can reduce the risks

rom malware.

See Computer viruses on page 227.

c In order to protect pupils, it would be better or the school to withdraw access to instant

messaging and social networks.

7 a A computer simulation is a model o the data in a real-world situation. A small business

could store its accounts on a spreadsheet and create a simulation o its uture perormance

under different conditions.

b A computer simulation makes it easier and cheaper to try out alternative scenarios to arrive

at the best solution to a problem.

See Simulation on page 173.

8 a Video-conerencing means using both video and audio eeds over a network to connect

people in a virtual meeting.

b Hardware needed or video-conerencing includes webcams and microphones.

c Advantages o video-conerencing are that meetings can be held at short notice and people

do not have to spend time travelling.

See Video conferencing on page 151.

9 a A games console, a microwave oven, an MP3 player, a DVD recorder and a sound system

are all controlled by a microprocessor.

b Tese devices may contribute to people living more separate lives it is much easier or

people in a amily to eat at different times, to watch V programmes separately (or the same

programme at different times).

See Automation and robotics on page 185.