Questions and Answers of Cambridge IGCSE Computer Science Coursebook

Explain what a database is.
Describe two advantages of using an electronic database over a paper-based system.
Match the correct term with its definition: A structure in which data is stored in a database Field Query A unique identifier for a record A collection of data about one single item in a database
Explain why it is important to give the correct data type to a field.
Bosire has a simple flat file database. Its table has two fields: name and telephone number.a. Explain why neither field is suitable as a primary key. What field could be added to create a primary
A database stores data in a table called Cars. The table structure includes fields called Colour, Engine Size and Number of Doors. Write an SQL query-by-example which searches for red or blue cars,
Why can unreliable data be of concern to a database user?
Discuss how and why 3D printing may become a more common technology in the home.
Describe three ways in which RAM differs from ROM.
Explain the difference between primary storage and secondary storage.
Explain how a hard disk drive reads and writes data.
What enables a Blu-ray disk to hold more data than a compact disk?
A company sends out an electronic catalogue its customers. Suggest a suitable storage medium and justify your choice with reasons.
A 16-bit Colour image is 4 inches x 1 inch in size, with a resolution of 600 dots per inch. Calculate the storage requirements for this image.
Explain why data on a magnetic tape may be accessed quickly or slowly.
Explain two reasons why solid-state storage is not as common in desktop PCs and laptops as hard disk drives.
What is meant by data losing its value?
Explain what is meant by an automatic backup.
Explain how phishing and pharming trick a user into giving up personal data.
Explain how anti-virus software may help to prevent distributed denial of service attacks.
Explain why computer security is more effective when anti-virus software and firewalls are used.
Describe how a proxy server can help keep data safe.
Explain the difference between symmetric and asymmetric encryption.
Describe what a protocol is and how protocols help protect data.
Define the term 'computer ethics.
Explain why ethics are necessary when using computers.
If a company gave you a free version of their software and encouraged you to try and improve it and share it with the online community, what kind of software would this be?
Explain how malware can be distributed using electronic communications.
Explain why it might be unethical to use an image taken from the internet in a commercial website.
Explain the difference between a variable and a constant. Give an example of when you would use each.
A programmer would like to store the following data:a. The user's nameb. The user's agec. The user's genderd. The user's quiz score.Give the most suitable data type for each item of data they want to
A teacher wants to work out the average test score for a class. They want to count and total the number of marks they enter to calculate the average.a. Explain how they would do this.b. The teacher
Explain why sequence is important when creating a program.
State one reason why a programmer would use an array.
A teacher wants to create a program that will allow them to write exam scores for a class to an array. There are 15 students in the class. Write a suitable pseudocode solution that will allow the
When creating an array, what are the two main things that we need to do?
Explain why comments should be used in pseudocode.
Explain why flowcharts are a useful design tool.
What symbol is used in a flowchart to represent a decision?
Design a pseudocode algorithm that will calculate the area and perimeter of a triangle. The user must choose which answer they want to be output.
Design a flowchart algorithm that makes sure a user only enters an integer in the range 1 to 10.
Design a flowchart algorithm for a simple drinks machine. The user can choose from tea, coffee, hot chocolate, orange juice and apple juice. if the user inputs a drink that is not listed an error
Amy has been asked to design an algorithm for a very large program. which design tool, pseudocode or flowchart, do you think would be most suitable? Explain your answer.
Describe what is meant by a library routine and suggest reasons why using such a routine is of benefit to a programmer.
Seema wishes to design an algorithm using a flowchart. Discuss the possible benefits and drawbacks of using a flowchart to design her algorithm.
Consider this algorithm:Complete the following trace table using the input data 4, 3,10,1, 0,15: value 0 nextValue 0 INPUT value INPUT nextValue WHILE nextValuc!-0#!-means not IF nextValue >
Explain the difference between a logic error and a syntax error.
Explain the difference between validation and verification.
Why is it important to use test data? Use examples in your answer.
Explain what is meant by the resolution of a display.
Vikram wants a new printer to take to university. He will be printing mainly essays and reports. State which type of printer would be most suitable and say why.
Explain why printers do not print in RGB.
Explain why LCD screens are more suited to portable devices than CRTs.
Explain what is meant by an output device.
Describe how a light sensor is used to read a barcode.
Describe how an infrared sensor works.
Explain how the use of moisture sensors can improve farming.
Explain two drawbacks of using motion sensors in a security system and suggest how they could be overcome.
Identify three different sensors that could be used to increase safety in a nuclear plant and describe how they would do this.
Define the term 'sensor'.
Explain how a 3D scanner works. Give an example in your answer.
Describe how a barcode works and what data they usually store.
Describe how an interactive whiteboard could be used to help train staff in a company.
Describe the fetch-execute cycle carried out in the von Neumann architecture.
Describe two benefits of using a digital camera over a film camera.
Explain why, when using a microphone, an analogue-to-digital converter is also needed when inputting data.
Explain how a touch screen device recognises that the screen is being touched.
Explain how a business could make use of QR codes.
Input devices can be either automatic or manual. Explain the difference between the two types. Give examples in your answer.
Explain what is meant by an input device.
Identify two input devices that could be present in a mobile phone.
In a system there are three switches and an alarm. The alarm will sound only if switches A and B are on. If switch C is turned on then the alarm will stop.a. Write the logic statement for this
The following truth table is for the logic statement X = A XOR (B AND C).Fill in the missing values to complete the truth table. Input Output B 1. 1 1.
Draw the logic circuit for the logic statement X = (A OR B) AND C.
Consider the following logic circuit:a. Write the logic statement to represent this logic gate.b. When A = 0, B = 0 and C = 1, output X= ……..c. When A = 1, B = 0 and C = 1, output X= ……… A
Describe the role of a logic gate in a logic circuit.
Tick (✓) which statements are true and false about low-level languages: Statement True False Low-level languages are a computer's native language Low-level languages need to be compiled before they
Describe the role of an assembler.
Explain the difference between a compiler and an interpreter.
Describe two advantages of high-level languages.
Describe three functions of an operating system.
Draw a line from each term to its correct definition: Connection between components in the CPU along which information travels Control unit Arithmetic and logic unit Unit that manages the flow of
Define the term 'register'.
Why can the use of cookies raise concern for an internet user?
Describe the difference between a static IP and a dynamic IP.
The Rock Factory uses a CSS to store the formatting instructions for their website. Explain what the advantages are for doing this.
Sarni wants to access a website that sells his favourite records. Explain how San will do this.
Explain how anti-virus software protects a computer.
Draw a tine to match the error detection and correction terms to the correct definitions: The number of bits transmitted are added up and this calculation is transmitted with the data Check digit Al
Describe two advantages of serial data transmission.
Explain what is meant by bit rate.
Kamil and his band want to record the new track they have written. How could the quality of their sound recording on a computer be improved?
Explain how ASCII is used to represent text so it can be processed by a computer.
Tom wants to send an image by email to his friend Nadia. He needs to reduce the size of the image in order to be able to send it via email. Describe two methods he could use to do this.
Tick (✓) the most suitable file extension for the following tasks: jpg .mp4 -mp3 .csv Storing holiday photos Storing holiday videos Storing a favourite song Storing data to be imported into other
The following instruction, written in machine code, is stored in computer memory: 110000011110Convert the code into hexadecimal notation.
Explain why hexadecimal notation is sometimes used to represent binary numbers.
What is meant by the term 'byte'?
A stopwatch uses six digits to display hours, minutes and seconds: 0 1:5 4:2 3It uses a nibble of binary data for each digit