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Hardware333

Answers to Revision questions: 3 Hardware 1 Cambridge IGCSE Computer Studies

Below each answer there is a page reference for the coursebook. Th is is there to help you focus your revision. If you fi 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 not represent the only possible answers.

1

See Chapter 3 as a whole.

2 a Th is is an example of magnetic ink characters. Th ey are read by a magnetic ink character recognition reader (MICR).

b Th is is an example of a barcode. It is read by a barcode reader.c Th is is an example of a specialised form for data collection by optical mark recognition. It is

read by an optical mark reader (OMR).See ‘Devices and methods for automatic data capture’ on page 60.

3 a A mouse is an input device.b A monitor is an output device.c A plotter is an output device.d A speaker is an output device.e A keyboard is an input device.f A scanner is an input device.

See ‘Input devices and their uses’ on page 49 and ‘Output devices and their uses’ on page 71.

4 a A barcode reader is used at a supermarket checkout to fi nd the price for an item by reading the data stored in the item’s barcode.

b A magnetic ink character recognition (MICR) reader is used in a bank to process cheques. Th e cheque number, bank sort code and account number are printed in magnetic ink so the MICR reader automatically enters them into the system. Th e operator has to enter the amount.

c An optical mark reader (OMR) is used to mark multiple-choice exam papers.See ‘Devices and methods for automatic data capture’ on page 60.

D. keyboard – input C. computer – storage and processor

E. telephone – communications

A. monitor screen – output

B. printer – output

© Cambridge University Press 2011 Answers to Revision questions: 3 Hardware 2 Cambridge IGCSE Computer Studies

5 Words can be input to a computer using a microphone with voice recognition soft ware and using a scanner with optical character recognition soft ware (OCR).

See ‘Sound and music capture devices’ on page 58 and ‘Devices and methods for automatic data capture’ on page 60.

6 A mouse is used on a desktop computer. A touchpad is used on a laptop. A touchscreen is used in a kiosk (e.g. a ticket machine in a train station or airport).

See ‘Manual input devices’ on page 49.

7 An ATM machine uses a numeric keypad and buttons at the side of the screen. It may also use a touchscreen for some buttons.

See ‘Manual input devices’ on page 49.

8 Temperature, pressure and humidity sensors can be used to input data in a control application.See ‘Sensors’ on page 66.

9 Backing storage is a long-term non-volatile storage that stores programs and data for future use. Computers need backing storage so that programs and data can be stored aft er the power has been switched off .

See ‘Backing storage’ on page 81.

10 a Magnetic tapes could be used to store large amounts of data where speed of access is not important.

b Magnetic tapes can be used in batch-processing applications, such as payroll and utility billing.c Magnetic tapes provide serial data access.

See ‘Magnetic storage media’ on page 82.

11 A DVD drive uses a more precise laser and can fi t more data on the disc than a CD, but DVD drives and media are more expensive than CD drives and media.

Similarly, Blu-ray discs store more data and are more expensive than DVD media. Recordable media cost more to produce than ROM discs, but allow the user to archive large

amounts of data. Re-writable media are even more expensive, but allow the user to record many times on the same disc.

See ‘Optical storage media’ on page 84.

12 A ‘backup’ is a copy of data. It is needed to recover data if the working medium becomes corrupted or damaged.

See page 84.

13 a ROM stands for ‘read-only memory’.b RAM stands for ‘random access memory’.c RAM is volatile storage and ROM is non-volatile storage. Data in RAM disappears when

a computer is switched off – it holds programs and data that are being worked on. Data in ROM cannot be changed aft er manufacture – it holds the computer’s boot information.

d Complete the following statements with ‘RAM’, ‘ROM’ or ‘backing storage’:i Backing storage stores a copy of your work when the computer is switched off .ii RAM stores application programs and data while the computer is running.iii ROM stores programs that must be available as soon as the computer is switched on.

See ‘Internal memory and storage devices and their uses’ on page 79.

© Cambridge University Press 2011 Answers to Revision questions: 3 Hardware 3 Cambridge IGCSE Computer Studies

14 Complete the following sentences by using the correct words from this list:

eight gigabytes memory RAM

a A byte is a unit of computer memory and it consists of eight bits.b A school computer may have two gigabytes of RAM.

See ‘Measuring the size of memory’ on page 80.

15 Indicate which of the following statements are true or false:a ROM stands for Read-Only Memory – TRUE.b Data can be saved in ROM – FALSE.c Th e internal memory of a computer can store soft ware and data – TRUE.d Data that changes is normally held in ROM – FALSE.e Data on magnetic tape has to be read serially – TRUE.f An airline booking system would probably use hard disk drive as backing storage – TRUE.g A CD-ROM is an optical disk – TRUE.

See ‘Internal memory and storage devices and their uses’ on page 79.