IGCSE Computer Science
What is the definition of an Input Device? - ANS Any device that allows a computer to receive data from
the outside world
How many types of scanners are there? - ANS 5
What type of scanner is used at airports to read passport pages? - ANS 2D Scanners
What type of scanner uses gamma rays? - ANS SPCET Scanners
What is the name of the input device that reads a series of dark and light lines of varying thickness? -
ANS Barcode Reader
What does the light line represent in a barcode? - ANS 0
Where is the most common place that Barcode Readers are used? - ANS Supermarkets
What does QR stand for in QR Code? - ANS Quick Response
How many times more data (approximately) can a QR code hold compared to a barcode? - ANS 200
What are 3 automatic adjustments that a microprocessor in a digital camera make? - ANS Shutter speed,
aperture size, size of image
What is the name of the cell that light passes through the lens onto in a digital camera? - ANS Light-
sensitive cell
,What determines the file size of a photograph? - ANS Number of pixels
What are two external factors that affect the quality of the photograph? - ANS Type of lens and lighting
What is the name for the most common input device? - ANS Keyboard
What do most computer systems use to prevent the microprocessor waiting for keys to be pressed? -
ANS Keyboard buffer
What injury are users prone to who do a lot of typing? - ANS Repetitive Strain Injury (RSI)
What are the two most common pointing devices? - ANS Mouse and trackerball
Which port connects the mouse to the computer? - ANS USB
What 3 common features do all mouses have? - ANS 2 buttons and a scroll wheel
What is the most common environment for where trackerballs are used? - ANS Control rooms
What is the name of the device that is used to input sound into a computer? - ANS Microphone
What is the name of the device that converts analogue data to digital data? - ANS Analogue to Digital
Converter (ADC)
What are the 3 types of touchscreen? - ANS Capacitive, Infra-red, Resistive
,What general type of touchscreen allows users to utilise whilst wearing gloves or using a stylus? - ANS
Resistive
What are the most common types of sensors? - ANS Monitoring and Control
What is the name of the device that converts digital data to analogue data? - ANS Digital to Analogue
Converter (DAC)
What component of a machine is responsible for controlling systems in control applications? - ANS
Actuators
How would monitoring sensors be used in a hospital? - ANS To monitor a patient's vital signs
What are two ways that control sensors are used on the street? - ANS Street lighting and traffic light
control
In street lighting, how long is a lamp left on or off for before readings are sampled again? - ANS 30
minutes
Benefits of high level languages? - ANS Easier to read and understand as the language is closer to human
language, easier to write in a shorter time, easier to debug at the development stage, easier to maintain
once in use
Examples of high level languages? - ANS C++, Delphi, Java, Pascal, Python, Visual basic.
Why do people use low level languages - ANS To make use of special hardware, to make use of special
machine-dependant instructions, to write code that doesn't take up a lot of space in primary memory, to
write code that performs tasks quickly
, Advantages and disadvantages of machine code - ANS difficult to understand, programmers don't
usually write in it, in binary (instructions that a computer understands)
Define a compiler - ANS A program that translates a program written in high level language into machine
code, translates one line at a time, distributed for general use, compiled programs are used without the
compiler.
Define an interpreter - ANS A program that reads a statement from a program in a high-level language,
performs the action specified and then does the same with the next statement over and over, doesn't
produce a translated program, used when a program is being developed, interpreted programs cant be
used without the interpreter
What does an assembler do? - ANS Translates a program in assembly language or machine code so that
it can be used by a computer to perform a required task, distributed for general use, assembled program
can be used without the assembler
Whats a syntax error? - ANS Where a program statement doesn't obey the rules of the programming
language
Define a logic error - ANS An error where the program doesn't do what the programmer wanted it to do
What happens when a runtime error occurs - ANS Error that occurs during the execution of a program.
Indicate bugs in the program or problems that the designers had anticipated but couldn't do anything
about. Running out of memory could cause a runtime error.
HTML structure and presentation - ANS HyperText Markup Language structure - essential part of HTML,
consisting of semantics and structural mark-up of the documents.
Presentation - the style of the document - how the document will appear on the user's computer screen.
What is the definition of an Input Device? - ANS Any device that allows a computer to receive data from
the outside world
How many types of scanners are there? - ANS 5
What type of scanner is used at airports to read passport pages? - ANS 2D Scanners
What type of scanner uses gamma rays? - ANS SPCET Scanners
What is the name of the input device that reads a series of dark and light lines of varying thickness? -
ANS Barcode Reader
What does the light line represent in a barcode? - ANS 0
Where is the most common place that Barcode Readers are used? - ANS Supermarkets
What does QR stand for in QR Code? - ANS Quick Response
How many times more data (approximately) can a QR code hold compared to a barcode? - ANS 200
What are 3 automatic adjustments that a microprocessor in a digital camera make? - ANS Shutter speed,
aperture size, size of image
What is the name of the cell that light passes through the lens onto in a digital camera? - ANS Light-
sensitive cell
,What determines the file size of a photograph? - ANS Number of pixels
What are two external factors that affect the quality of the photograph? - ANS Type of lens and lighting
What is the name for the most common input device? - ANS Keyboard
What do most computer systems use to prevent the microprocessor waiting for keys to be pressed? -
ANS Keyboard buffer
What injury are users prone to who do a lot of typing? - ANS Repetitive Strain Injury (RSI)
What are the two most common pointing devices? - ANS Mouse and trackerball
Which port connects the mouse to the computer? - ANS USB
What 3 common features do all mouses have? - ANS 2 buttons and a scroll wheel
What is the most common environment for where trackerballs are used? - ANS Control rooms
What is the name of the device that is used to input sound into a computer? - ANS Microphone
What is the name of the device that converts analogue data to digital data? - ANS Analogue to Digital
Converter (ADC)
What are the 3 types of touchscreen? - ANS Capacitive, Infra-red, Resistive
,What general type of touchscreen allows users to utilise whilst wearing gloves or using a stylus? - ANS
Resistive
What are the most common types of sensors? - ANS Monitoring and Control
What is the name of the device that converts digital data to analogue data? - ANS Digital to Analogue
Converter (DAC)
What component of a machine is responsible for controlling systems in control applications? - ANS
Actuators
How would monitoring sensors be used in a hospital? - ANS To monitor a patient's vital signs
What are two ways that control sensors are used on the street? - ANS Street lighting and traffic light
control
In street lighting, how long is a lamp left on or off for before readings are sampled again? - ANS 30
minutes
Benefits of high level languages? - ANS Easier to read and understand as the language is closer to human
language, easier to write in a shorter time, easier to debug at the development stage, easier to maintain
once in use
Examples of high level languages? - ANS C++, Delphi, Java, Pascal, Python, Visual basic.
Why do people use low level languages - ANS To make use of special hardware, to make use of special
machine-dependant instructions, to write code that doesn't take up a lot of space in primary memory, to
write code that performs tasks quickly
, Advantages and disadvantages of machine code - ANS difficult to understand, programmers don't
usually write in it, in binary (instructions that a computer understands)
Define a compiler - ANS A program that translates a program written in high level language into machine
code, translates one line at a time, distributed for general use, compiled programs are used without the
compiler.
Define an interpreter - ANS A program that reads a statement from a program in a high-level language,
performs the action specified and then does the same with the next statement over and over, doesn't
produce a translated program, used when a program is being developed, interpreted programs cant be
used without the interpreter
What does an assembler do? - ANS Translates a program in assembly language or machine code so that
it can be used by a computer to perform a required task, distributed for general use, assembled program
can be used without the assembler
Whats a syntax error? - ANS Where a program statement doesn't obey the rules of the programming
language
Define a logic error - ANS An error where the program doesn't do what the programmer wanted it to do
What happens when a runtime error occurs - ANS Error that occurs during the execution of a program.
Indicate bugs in the program or problems that the designers had anticipated but couldn't do anything
about. Running out of memory could cause a runtime error.
HTML structure and presentation - ANS HyperText Markup Language structure - essential part of HTML,
consisting of semantics and structural mark-up of the documents.
Presentation - the style of the document - how the document will appear on the user's computer screen.
