IGCSE COMPUTER SCIENCE (ALL)
EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
What is the definition of an Input Device? - Answer-Any device that allows a computer
to receive data from the outside world
How many types of scanners are there? - Answer-5
What type of scanner is used at airports to read passport pages? - Answer-2D
Scanners
What type of scanner uses gamma rays? - Answer-SPCET Scanners
What is the name of the input device that reads a series of dark and light lines of
varying thickness? - Answer-Barcode Reader
What does the light line represent in a barcode? - Answer-0
Where is the most common place that Barcode Readers are used? - Answer-
Supermarkets
What does QR stand for in QR Code? - Answer-Quick Response
How many times more data (approximately) can a QR code hold compared to a
barcode? - Answer-200
What are 3 automatic adjustments that a microprocessor in a digital camera make? -
Answer-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?
- Answer-Light-sensitive cell
What determines the file size of a photograph? - Answer-Number of pixels
What are two external factors that affect the quality of the photograph? - Answer-Type
of lens and lighting
What is the name for the most common input device? - Answer-Keyboard
What do most computer systems use to prevent the microprocessor waiting for keys to
be pressed? - Answer-Keyboard buffer
,What injury are users prone to who do a lot of typing? - Answer-Repetitive Strain Injury
(RSI)
What are the two most common pointing devices? - Answer-Mouse and trackerball
Which port connects the mouse to the computer? - Answer-USB
What 3 common features do all mouses have? - Answer-2 buttons and a scroll wheel
What is the most common environment for where trackerballs are used? - Answer-
Control rooms
What is the name of the device that is used to input sound into a computer? - Answer-
Microphone
What is the name of the device that converts analogue data to digital data? - Answer-
Analogue to Digital Converter (ADC)
What are the 3 types of touchscreen? - Answer-Capacitive, Infra-red, Resistive
What general type of touchscreen allows users to utilise whilst wearing gloves or using
a stylus? - Answer-Resistive
What are the most common types of sensors? - Answer-Monitoring and Control
What is the name of the device that converts digital data to analogue data? - Answer-
Digital to Analogue Converter (DAC)
What component of a machine is responsible for controlling systems in control
applications? - Answer-Actuators
How would monitoring sensors be used in a hospital? - Answer-To monitor a patient's
vital signs
What are two ways that control sensors are used on the street? - Answer-Street lighting
and traffic light control
In street lighting, how long is a lamp left on or off for before readings are sampled
again? - Answer-30 minutes
Benefits of high level languages? - Answer-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? - Answer-C++, Delphi, Java, Pascal, Python, Visual
basic.
, Why do people use low level languages - Answer-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 - Answer-difficult to understand,
programmers don't usually write in it, in binary (instructions that a computer
understands)
Define a compiler - Answer-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 - Answer-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? - Answer-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? - Answer-Where a program statement doesn't obey the rules of
the programming language
Define a logic error - Answer-An error where the program doesn't do what the
programmer wanted it to do
What happens when a runtime error occurs - Answer-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 - Answer-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.
ISP - Answer-Internet Service Provider - a company that provides a user with access to
the internet. They usually charge a monthly fee. The ISP will give a user an account and
an email address
IP - Answer-Internet Protocol - each device is given an IP address as soon as it
accesses the internet. It changes every time that the device goes on the internet
EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
What is the definition of an Input Device? - Answer-Any device that allows a computer
to receive data from the outside world
How many types of scanners are there? - Answer-5
What type of scanner is used at airports to read passport pages? - Answer-2D
Scanners
What type of scanner uses gamma rays? - Answer-SPCET Scanners
What is the name of the input device that reads a series of dark and light lines of
varying thickness? - Answer-Barcode Reader
What does the light line represent in a barcode? - Answer-0
Where is the most common place that Barcode Readers are used? - Answer-
Supermarkets
What does QR stand for in QR Code? - Answer-Quick Response
How many times more data (approximately) can a QR code hold compared to a
barcode? - Answer-200
What are 3 automatic adjustments that a microprocessor in a digital camera make? -
Answer-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?
- Answer-Light-sensitive cell
What determines the file size of a photograph? - Answer-Number of pixels
What are two external factors that affect the quality of the photograph? - Answer-Type
of lens and lighting
What is the name for the most common input device? - Answer-Keyboard
What do most computer systems use to prevent the microprocessor waiting for keys to
be pressed? - Answer-Keyboard buffer
,What injury are users prone to who do a lot of typing? - Answer-Repetitive Strain Injury
(RSI)
What are the two most common pointing devices? - Answer-Mouse and trackerball
Which port connects the mouse to the computer? - Answer-USB
What 3 common features do all mouses have? - Answer-2 buttons and a scroll wheel
What is the most common environment for where trackerballs are used? - Answer-
Control rooms
What is the name of the device that is used to input sound into a computer? - Answer-
Microphone
What is the name of the device that converts analogue data to digital data? - Answer-
Analogue to Digital Converter (ADC)
What are the 3 types of touchscreen? - Answer-Capacitive, Infra-red, Resistive
What general type of touchscreen allows users to utilise whilst wearing gloves or using
a stylus? - Answer-Resistive
What are the most common types of sensors? - Answer-Monitoring and Control
What is the name of the device that converts digital data to analogue data? - Answer-
Digital to Analogue Converter (DAC)
What component of a machine is responsible for controlling systems in control
applications? - Answer-Actuators
How would monitoring sensors be used in a hospital? - Answer-To monitor a patient's
vital signs
What are two ways that control sensors are used on the street? - Answer-Street lighting
and traffic light control
In street lighting, how long is a lamp left on or off for before readings are sampled
again? - Answer-30 minutes
Benefits of high level languages? - Answer-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? - Answer-C++, Delphi, Java, Pascal, Python, Visual
basic.
, Why do people use low level languages - Answer-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 - Answer-difficult to understand,
programmers don't usually write in it, in binary (instructions that a computer
understands)
Define a compiler - Answer-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 - Answer-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? - Answer-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? - Answer-Where a program statement doesn't obey the rules of
the programming language
Define a logic error - Answer-An error where the program doesn't do what the
programmer wanted it to do
What happens when a runtime error occurs - Answer-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 - Answer-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.
ISP - Answer-Internet Service Provider - a company that provides a user with access to
the internet. They usually charge a monthly fee. The ISP will give a user an account and
an email address
IP - Answer-Internet Protocol - each device is given an IP address as soon as it
accesses the internet. It changes every time that the device goes on the internet
