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1

Name three different sensors. Sensor 1 Sensor 2 Sensor 3

3. Hardware  →  3.2. Input and output devices

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2

The diagram below shows five logic gate symbols and five names. Draw a line between each logic gate symbol and its correct name. AND Logic Gate Symbol Name NOT NOR XOR NAND

10. Boolean logic  →  10. Boolean logic

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3

A company has a number of offices on one site. Data are transmitted, using a wired network, from one office and stored at another office. State, with reasons, which data transmission, serial or parallel, should be used. Type Reasons The two registers’ contents shown include parity bits. Parity bit Register 1 Register 2 State which type of parity each register is using. Register 1 Register 2 Give one method, other than parity checking, that could be used for checking for errors in the transmission of data. Method

2. Data transmission  →  2.2. Methods of error detection

2. Data transmission  →  2.1. Types and methods of data transmission

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4

A simple symmetric encryption system is used to encrypt messages. Each letter of the alphabet is substituted by another letter. Plain text a b c d e f g h i j k l m n o p q r s t u v w x y z Cypher text v p n a q b r u z s c o y k w f x i e m d j t l h g Convert the following plain text to cypher text. Plain text: d a t a s e c u r i t y Cypher text: A new cypher text is created by shifting each letter of the alphabet five places to the right. Show the new cypher text below. Plain text a b c d e f g h i j k l m n o p q r s t u v w x y z New cypher text State, giving a reason, which cypher text would be more secure.

2. Data transmission  →  2.3. Encryption

1. Data representation  →  1.2. Text, sound and images

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5

Give the meaning of the following terms. HTML http https

5. The internet and its uses  →  5.1. The internet and the world wide web

5. The internet and its uses  →  5.3. Cyber security

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6

The diagram shows five operating system functions and five descriptions. Draw a line between each operating system function and its description. Function Description Interrupt Many processes appear to run simultaneously Utility Data are temporarily held in a buffer waiting for an output device to access it Memory management A signal that causes the operating system to take a specified action Spooling A program that performs a specific task required for the operation of a computer system Multitasking A process of assigning blocks of memory to programs running in a computer

4. Software  →  4.1. Types of software and interrupts

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7

A high definition video and a large text file are to be sent as email attachments. Both files are compressed before sending. Each file is compressed using a different type of data compression algorithm. Explain, with reasons, which type of data compression algorithm should be chosen for each file.

1. Data representation  →  1.3. Data storage and compression

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8

A register in a computer contains binary digits. The contents of the register could represent a binary integer. Convert the binary integer to denary and hexadecimal. Denary Hexadecimal The contents of the register could represent the ASCII value for the single denary digit ‘7’. Write down the ASCII value for ‘9’ in binary, denary and hexadecimal. Binary Denary Hexadecimal Write in Register X the binary number you would use with AND gates to convert the ASCII value of ‘7’ to its binary integer value. ASCII Register X

1. Data representation  →  1.1. Number systems

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9

Passwords are used to keep data safe. Explain the differences between a text-based password and a biometric password.

5. The internet and its uses  →  5.3. Cyber security

2. Data transmission  →  2.3. Encryption

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10

Describe the differences between a barcode and a Quick Response (QR) code.

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11

Three programmers are working on different projects: • Alice is developing a program written in a low-level language • Akbar is developing a program written in a high-level language • Alex is preparing a program written in a high-level language for sale State, with reasons, which type of translator each programmer should use. Each programmer should be using a different type of translator. Alice Akbar Alex

4. Software  →  4.2. Types of programming language, translators and integrated development environments (IDEs)

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12

Identify three uses for hexadecimal and for each one give an example of hexadecimal that matches the use. Use 1 Example Use 2 Example Use 3 Example Explain why hexadecimal is used to represent binary numbers.

1. Data representation  →  1.1. Number systems

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13

Explain what is meant by primary, secondary and off-line storage. Give an example of each. Primary storage Example Secondary storage Example Off-line storage Example A set of photographs has been taken for a wedding. All the guests are to be sent digitally stored copies through the ordinary postal service. There are fifty photographs and each photograph is between 1.8 and 2.5 megabytes in size. Work out the maximum storage space required for a set of photographs. State, with a reason, a suitable medium to use for the copies to be sent to the guests. Maximum storage space Medium Reason

3. Hardware  →  3.3. Data storage

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14

A system controls the flow of vehicles through a barrier based on three lights, A, B and C. When a light is red, the signal is zero. When a light is green, the signal is one. The barrier will open when the output X is one. The barrier opens if either: • light A is red and lights B and C are both green or • light A is green and lights B and C are both red Design a logic circuit for the system. A B C X Complete the truth table for the system given at the start of Question 14. A B C Working space X

10. Boolean logic  →  10. Boolean logic

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