0478_m19_qp_12 - revisedeck

0478_m19_qp_12

A paper of Computer Science, 0478

Questions:

7

Year:

2019

Paper:

1

Variant:

2

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1

Elle has a file stored on her computer that is 20 MB in size. Jordan has a file that is 10 GB in size. Tick (3) to show which is the larger file. File size Tick (3) 20 MB 10 GB Bob has a file stored on his computer that is 3500 kB in size. Gerty has a file that is 3 MB in size. Tick (3) to show which is the larger file. File size Tick (3) 3500 kB 3 MB

1. Data representation → 1.3. Data storage and compression

8. Programming → 8.3. File handling

Open

2

Many computer systems have an input device and an output device. State what is meant by an input device. Give an example of an input device. State what is meant by an output device. Give an example of an output device.

3. Hardware → 3.2. Input and output devices

Open

3

A long distance running race uses an electronic counter that counts each competitor who finishes the race. The count is stored as binary in a 12-bit register. A denary value of the count is displayed on a screen above the finish line. The screen currently displays: State the binary value that is currently stored to display the count shown. More competitors cross the finish line and the screen now displays: State the binary value that is currently stored to display the count shown. At the end of the race the binary value stored is: Give the denary value that would be displayed on the screen at the end of the race. Show your working. Screen display: Sensors are used at the finish line to identify the number of competitors who finish the race. Identify two different sensors that could be used to identify the number of competitors. Sensor 1 Sensor 2 The sensors are used with a microprocessor to count how many competitors finish the race. Explain how the sensor and the microprocessor are used.

1. Data representation → 1.1. Number systems

3. Hardware → 3.2. Input and output devices

Open

4

Darius is writing a computer program that allows binary values to be calculated. Darius chooses to write the program in a high-level language rather than a low-level language. Explain why Darius chooses to write the program in a high-level language. Darius will use a translator to translate the program. He could use a compiler or an interpreter. Five statements are given about compilers and interpreters. Tick (3) to show if the statement applies to a Compiler or an Interpreter. Statements may apply to both. Statement Compiler (3) Interpreter (3) A report of errors is produced at the end of translation. The program is translated one line at a time. The program is translated from high-level language into machine code. An executable file is produced. The program will not run at all if an error is detected. Darius is sending several programs that he has created to his friend Selma. He wants to compress the files to send them as he needs to attach them to an email. Darius tells Selma he is going to use lossy compression. Selma tells him that he should use lossless instead. Explain why Selma tells Darius to use lossless compression instead of lossy. Errors can occur when data is transmitted, stored or entered into a system. Darius could use an error detection method to find whether errors have occurred. One error detection method he could use is a checksum. Describe how a checksum detects errors. State three other error detection methods that Darius could use. Method 1 Method 2 Method 3

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

8. Programming → 8.3. File handling

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5

Consider the following logic statement: X = 1 if ((A is 1 NAND C is 1) NOR A is NOT 1) OR (B is 1 AND C is NOT 1) Draw a logic circuit that represents the given logic statement. Your logic gates must have a maximum of two inputs. Do not simplify the logic statement. A B C X Complete the truth table for the given logic statement. A B C Working space X

10. Boolean logic → 10. Boolean logic

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6

Nadia purchases a printer to print out her homework. She connects the printer to her computer using USB. Explain what is meant by USB. Nadia’s printer uses powdered toner rather than liquid ink. State the type of printer Nadia has purchased. Give two benefits of using this type of printer. Benefit 1 Benefit 2 Give one drawback of using this type of printer. Drawback 1 Nadia uses several types of computer storage for her homework and other projects. Five examples of computer storage are given. Tick (3) to show if the computer storage is Primary, Secondary or Off-line. Storage example Primary (3) Secondary (3) Off-line (3) Solid state drive (SSD) Blu-ray disc USB flash memory Random access memory (RAM) Read only memory (ROM) Nadia is considering purchasing a magnetic storage device. Describe how a magnetic storage device stores data. Give two advantages of using a magnetic storage device rather than a solid state storage device. Advantage 1 Advantage 2

3. Hardware → 3.3. Data storage

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7

Arya regularly uses the Internet as a research tool for her school projects. Identify and describe three risks to Arya’s computer when she is using the Internet for research. Risk 1 Description Risk 2 Description Risk 3 Description

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

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

Open