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1

Computers use a character set to convert text into binary. One character set that can be used is ASCII. Each letter in ASCII can also be represented as a denary value. The word BUS has the denary values: B U S Convert the denary values into 8-bit binary. Each letter in ASCII can also be represented as a hexadecimal value. The word KEY has the 8-bit binary values: K E Y Convert the three 8-bit binary values into hexadecimal. Give three other uses of hexadecimal notation in computer science. State two benefits of using hexadecimal notation to represent binary values. Benefit 1 Benefit 2

1. Data representation  →  1.1. Number systems

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2

A computer uses RAM and ROM to store data. The table contains three statements about RAM or ROM. Tick (✓) to show whether each statement describes RAM or ROM. Statement RAM (✓) ROM (✓) Stores the programs and data that are currently in use Used to boot up the computer when power is turned on Contents are retained when power is turned off Circle the storage category that includes both RAM and ROM. Primary Secondary Off-line Explain what is meant by off-line storage.

3. Hardware  →  3.3. Data storage

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3

A greenhouse uses a system to monitor the conditions that plants need to grow. The inputs to the system are: Input Binary value Condition W Window is open Window is closed T Temperature >=26 °C Temperature =50% Humidity =26 °C or temperature =50% Draw a logic circuit to represent the system. W T X H

10. Boolean logic  →  10. Boolean logic

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4

Identify three security issues that can put a computer system at risk. Security issue 1 Security issue 2 Security issue 3 Explain how a firewall can help to protect a computer system from security issues.

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

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5

Karina is taking her Computer Science examination. She has three questions to answer about output devices. For the first question she writes the answer: “It is a high powered laser that cuts materials such as thin metals or wood.” Identify the output device that Karina is describing. For the second question she writes the answer: “The screen is made up of blocks of red, green and blue pixels. The screen uses layers of different types of liquid.” Identify the output device that Karina is describing. For the third question she writes the answer: “It is responsible for powering and moving a motor in machinery, such as a robot arm in a factory.” Identify the output device that Karina is describing. Karina correctly answers another examination question about some more output devices. Five different terms have been removed from her answer. Complete the sentences in Karina’s answer, using the list given. Not all terms in the list need to be used. • 3D • digital light projector • inkjet • interactive whiteboard • laser • rotating • scanning • sliding • speaker • thermal bubble An allows a user to write on a surface using a pen, the text and drawings can then be captured and stored for later use. An printer produces a hard copy of a document using and piezoelectric technology. A printer uses a drum, and positive and negative charges, to produce a hard copy of a document.

3. Hardware  →  3.2. Input and output devices

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6

Many programmers write computer programs in high-level languages. The programs need to be translated into machine code to be read by the computer. State two types of translator that can be used. Translator 1 Translator 2 Explain two reasons why a computer programmer may choose to write a program in a high- level language, rather than a low-level language. Reason 1 Reason 2 Three examples of computer code are given in the table. Tick (✓) to show whether each example of computer code is High-level language, Assembly language or Machine code. Computer code High-level language (✓) Assembly language (✓) Machine code (✓) FOR X = 1 TO 10 PRINT X NEXT X INP X STA X LDA Y

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

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7

Six internet terms and six definitions are listed. Draw a line to connect each term to a correct definition. Internet term Definition Browser Internet Service Provider (ISP) Hyper Text Transfer Protocol (HTTP) Uniform Resource Locator (URL) MAC address IP address A program that allows a user to view webpages The main protocol that governs the transmission of data using the Internet The website address that is typed into the address bar An address given to each device on a network. It is provided by the network A unique address given to a device on a network. It is provided by the manufacturer A company that provides a connection to access the Internet

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

3. Hardware  →  3.4. Network hardware

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8

Describe the purpose of an interrupt in a computer system.

4. Software  →  4.1. Types of software and interrupts

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9

Computers can transmit data using different methods. Describe the three data transmission methods given. Serial data transmission Parallel data transmission Duplex data transmission Data can sometimes be corrupted when it is transmitted from one computer to another, causing errors to be present in the data. Identify and describe three methods of error detection that could be used to see if an error has occurred. Error detection method 1 Description Error detection method 2 Description Error detection method 3 Description

2. Data transmission  →  2.2. Methods of error detection

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

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10

A system uses pH sensors and a microprocessor to help monitor pollution in a river. The pH of the water should be between 6 and 8. The system outputs an alert if the pH of the water is not in this range. Explain how the system uses the pH sensors and the microprocessor to help monitor the pollution.

6. Automated and emerging technologies  →  6.1. Automated systems

3. Hardware  →  3.2. Input and output devices

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