add the following bytes

11011000

01100000

__________

__________

Your answer should be one of the following

00011000

 (1)00111000

(1)00001100

what are the following file types used for

1. HTML
2. JPG
3. MP3
4. PDF

1. HTML: Language used to create webpage content
2. jpg: images/photos
3. mp3: sound/sudio/music files
4. pdf: documents

Most Computer systems use at least one storage device,

Explain one reason why a secondary storage device is needed in most computer systems

• To store the files/eg operating system

Even when the system is switched off/which must be non-volatile.

ROM will store stystem data even when the system is switched off this is known as secondary storage devices

1. Some secondary storage devices are magnetic and others are solid state. Describe the characteristics of magnetic and solid state secondary storage.

Magnetic.

• Normally large and very cheap
• Used as main storage in most computers
• has moving parts so no good when moving about

Solid State

 . Expensive

. no moving parts so easy to move about

. replaces floppy disks etc

A school haS all of its computers in a local area network (LAN)

State two benefits of a LAN

•  Can share files/many people can work on the  on same files at the same time
•  Can share hardware resources i.e. a printer
•  Can access their files from any computer/classroom
•  Can work together from different computers using instant messaging
• Centralised deployment of software to all computers

• Passwords to protect user accounts
• Network restrictions
• firewalls to prevent unatuorised access / hacking into the network

When recording a sound file on a computer, the sound needs to be sampled...

Describe how sampling is used when storing sound

• The height/amplitutde of the sound wave is measured at regular intervals
• sound is converted to binary

• If the interval is smaller / you do not get the full effect of the sound and the quality is not so good

• If you make your sample bigger the file is larger but the sound is far bettr and closer to the original

• The accedent and emergency department of a hospital uses a computer systme to decide what order in which patients are treated

Describe advantages of using a computer system instead of a person to decide the order, also describe why this system needs to be reliable

• Computers are more stematic than human and will give more consistent results
• Software can be deployed in several departments
• easier to analyse records

reliability

• Critical application, lives may be at stake if the system crashes
• loss of data or power is a bad thing

Computers have lots of electrical circuits tht have two states

either off or on i.e. 1/0

In the ASCII character set, the character codes for the first three capital letters are shown as

• A - 01000001
• B - 01000010
• C - 01000011

State how the ASCII character set is used to represent text in computer

Each character is assigned a unique character code which is a binary number

Convert the word CAB into binary using ASCII character set

010000110100000101000010

 ASCII uses 8 bits...

 ... and so can only represent 255/256 distinct characters...

 ..many more characters are needed for coping with all languages

 ASCII does contain characters used in some languages

Charley is writing a program for music students. To make sure that there are no logic erros in the program, Charey uses a test plan

• Describe what is meant by a logic error

 The error does not prevent program running…

 But it does not produce the expected output/it does not do what the programmer expected



The program uses the letters in the following list to represent musical notes

CDEFGAB

When the user inputs a letter from this list, the program outpus the next three notes in the list. If it gets to the end of the list, it starts again from the beginning, so the next note after B is C.

Complete a test plan by stating, for each input data, the expected outcome and reason for test.

C      expected outcome      reason for test

A      expected outcome      reason for test

H      expected outcome      reason for test

C     DEF      Checks the output is the next three letters in the list

A     BCD      Checks the output goes back to the beginning of the list

H     Error message     Not a valid/ exising note

A User buys a new computer with an operating system and some utilities

State two functions of the operating system

• Provides interfaces between user and comupter
• Provides a platform for software to run
• manages peripherals used by the system like printers, mouse, keyboard
• manages memory

In the table are some utilities

are the disk or security utilities

used for security      Disk

Antivirus 

Defragmenter

File Transfer

Firewall

Antivirus      used for security

Defragmenter disk

file transfer     disk

firewall    used for security

Some of the softwre in His computer is open source

Describe what is meant by open source software

• The source code can be distributed
• the customer can modify the code
• the customer can redistribute (swap) the code

A structured organised store of data

data can be queried

• When a person jones a website, they need to enter some personal data which is validated using rules. Fore example, the date of birth must be in the past

state one rule for each

Email address

Gender

Password

Email address

Must contain an @ sign

Must contain a full stop after the @ sign

Gender

Must be Male Female or Other

Password

Must have a given minimum length

Must contain a non-letter

Each user can upload several pictures. Each picture has a date and comment.

The personal data of users is stored in a table called USER the data about the pictures is stored in a separte table called PICTURE

Explain why the data about the pictures should be in a seperate table. and how the tables can be linked

• Avoids data repetition of the personal details of the user
• A user can have more than one picture
• The primary key of the USER is stored in the PICTURE table where it is called a foreign key

Jim is writing a prgram to calculate the wages of workers in a factory

Jim uses an Integrated Development Environment (IDE) to create the program

Describe two tools in an IDE that can help him when creating the program

• Colour coding keywords
• Auto completes code as you type
• debugging tools
• highlights errors in the code

Workers sometimes get a £50 bonus

here is the algorithm used to calulate whether a worker should get a bonus

Limit = 200

INPUT WagesEarned

IF WagesEarned < Limit THEN

     Pay = WagesEarned

Else

     Pay = WagesEarned + 50

END IF

State the value of pay after this code is run for each of the follwing

WagesEarned = 50    Pay = _____________

WagesEarned = 200  Pay = ____________

50

250

The wages earned by a worker is either £2 for every teddy bear they have made or £5 for every hour they have worked which ever is larger.

Write an algorithm that:

• allows the user to input the number of teddy bears made and the number of hours worked
• calculates the wages for the number of teddy bears made
• calculates the wages for the number of hours worked
• outputs the larger of the two results

INPUT TeddyBears

INPUT Hours

PerTeddyBear = 2 * TeddyBears

PerHour = 5 * Hours

IF PerTeddyBear > PerHour THEN

    OUTPUT PerTeddyBear

ELSE

    OUTPUT PerHour

END IF