Computer Science Post-Easter Assessment Past Paper Questions
Describe how the data is read from a Compact Disc (CD). [4]
- (Red) laser is used - (Laser beams) shines onto surface of the disk - It is rotated (at a constant speed) to be read - Surface is covered in a track (that spirals from the centre) - Data is represented on the surface using pits and lands - Pits and lands represent binary values - Pits reflect light back differently (to the area in between/land) - Optical device can determine the binary value from the light reflection
State what is meant parallel data transmission [1]
- 8 bits/1 byte/multiple bits sent at a time - using many/multiple/8 wires/lines
Name the storage device, and category of storage (from primary, secondary and off-line) from the description: optical media that uses blue laser technology to read and write data on the media surface; it uses a single 1.1 mm polycarbonate disc [2]
- Blu-ray - Off-line
Describe two differences between Blu-ray discs and DVDs. [2]
- Blu-ray discs use blue/violet lasers rather than red lasers as used by DVDs - storage capacity of Blu-ray discs is much higher than standard DVDs - Blu-ray discs use one polycarbonate layer; DVDs use two layers
Give an example of off-line storage and explain how it is used [2]
- CD/DVD/Blu-ray/Flash Memory/USB stick/Removable HDD/Removable SSD: stores files / applications (by example)
Explain what is meant by the term 'high-level language'. [2]
- Closer to human language // closer to English - Independent of a particular type of computer/device/platform // portable language - A language such as Python, Java, Pascal, etc.
Name the storage device, and category of storage (from primary, secondary and off-line) from the description: optical media which uses one spiral track; red lasers are used to read and write data on the media surface; makes use of dual-layering technology to increase the storage capacity [2]
- DVD - Off-line
Describe two differences between DVD and DVD-RAM. [2]
- DVD has one spiral track; DVD-RAM has several concentric tracks - DVD-RAM can be written to and read from at the same time; DVD only allows the read operation to occur
Name the storage device, and category of storage (from primary, secondary and off-line) from the description: optical media which uses concentric tracks to store the data; this allows read and write operations to be carried out at the same time [2]
- DVD-RAM - Off-line
To process an instruction, a central processing unit (CPU) goes through a cycle that has three main stages. Name each stage in this cycle. [3]
- Fetch - Decode - Execute
Give an example of secondary storage and explain how it is used [2]
- HDD / SSD: stores files / applications (by example)
Explain why many web servers still use hard disc drive (HDD) technology. [2]
- HDD is cheaper for larger amounts of storage space - Expensive to change the technology // HDD are trusted technology - No requirement for the increased speed of SSD
Give three different ways that data can be accidentally damaged. [3]
- Human error (e.g. deleting/overwriting data) - Physical damage - Power failure/surge - Hardware failure - Software crashing
Describe what is meant by an Internet Protocol (IP) address. [4]
- IP address is used to identify a device (on the Internet / network) - IP address is allocated by the network/ ISP - Can be used in place of URL - IP addresses can be IPv4 or IPv6
State what is meant by IP address [1]
- Internet Protocol (address)
Give the names of two registers. [2]
- PC (Program Counter) - MAR (Memory Address Register) - MDR (Memory Data Register) - CIR or IR ((Current) Instruction Register) - ACC (Accumulator)
Describe the differences between primary and secondary storage. [4]
- Primary RAM and ROM - Secondary HDD and SSD - Primary has both volatile and non-volatile - Secondary is non-volatile - Primary is directly accessible by CPU - Secondary is not directly accessible by CPU - Primary is internal to computer - Secondary can be internal or external to the computer - Primary stores boot up instructions and can hold data whilst being processed - Secondary stores files/software - Primary has faster access speed - Secondary has a slower access speed
Give an example of primary storage and explain how it is used [2]
- RAM: stores OS when running / data currently in use / instructions currently in use - ROM: stores boot instructions / BIOS
Name the storage device, and category of storage (from primary, secondary and off-line) from the description: non-volatile memory chip; contents of the chip cannot be altered; it is often used to store the start-up routines in a computer (e.g. the BIOS) [2]
- ROM - Primary
Name the storage device, and category of storage (from primary, secondary and off-line) from the description: non-volatile memory device that uses NAND flash memories (which consist of millions of transistors wired in series on single circuit boards) [2]
- SSD - Secondary
State three tasks carried out by anti-virus software [3]
- Scans files for viruses // detects/identifies a virus - Can constantly run in background - Can run a scheduled scan - Can delete a virus - Notifies user of a possible virus
An air conditioning system is used to control the temperature in a hospital. The air conditioning system uses temperature sensors and a microprocessor. The temperature must remain between 21°C and 24°C. Describe how the sensors and the microprocessor are used to control the temperature of the hospital. [6]
- Sensor(s) send data/signals to the microprocessor - Analogue signal/data from sensor is converted to digital (using ADC) - Microprocessor compares data value against set boundaries / pre-set data - If value between 21 and 24, no action taken - If value > 24 °C / signal is sent from microprocessor to turn conditioning unit ON//Set to cold - If value is < 21 °C signal is sent from microprocessor to turn conditioning unit ON//Set to warm - Process is repeated for a continuous operation
Describe how the sensors and a microprocessor are used to monitor a process [5]
- Sensors send signals to microprocessor - Analogue signals are converted to digital (using ADC) - Microprocessor compares value to stored value ... - ... If out of range / matches stored values ... - ... signal sent to alert workers (e.g. sound alarm) - ... microprocessor send signal to cause an action to occur e.g. cool a process down, heat a process up, add a chemical - ... no action taken - Output/record readings - Monitoring is continuous
Describe the stored program concept when applied to the Von Neumann model. [4]
- The program is stored on a secondary storage device - Data and instructions are moved to memory / RAM - Data and instructions are stored in the same memory / RAM - Data and instructions are moved to registers to be executed - Instructions are fetched one at a time
Describe how an interpreter translates a computer program. [3]
- Translates high-level language into machine code/low level language − Translates (the source code) line by line/statement by statement - Stops if it finds an error - Will only continue when error is fixed
State three ways in which one can reduce the risk of a computer getting a computer virus, other than anti-virus software [3]
- Use a firewall - Use of a proxy server - Do not use / download software / files from unknown sources - Limiting access to the computer
Give three reasons for using a USB port. [3]
- automatically detects the hardware/installs drivers - plug only goes in one way/can't connect incorrectly - has become the industry standard/universally used
State two advantages of using a low-level language [2]
- can work directly on memory locations - can be executed faster - translated program requires less memory
Give one application of serial data transmission [1]
- connect computer to a modem
Give the names of two buses. [2]
- control - data - address
State two advantages of using a high-level language [2]
- easier/faster to write code as uses English-like statements - easier to modify as uses English-like statements - easier to debug as uses English-like statements
Give one benefit of parallel data transmission [1]
- faster rate of data transmission
Give a reason why a bank system asks for four random characters from their password [1]
- hacker never finds all characters on the first hack - hacker needs to hack the system several times to gain the whole password
Modern LCD monitors and televisions use LED back-lit technology. Give two advantages of using this new technology compared to the older cold cathode fluorescent lamp (CCFL) method. [2]
- higher resolution - much thinner monitors possible/lighter weight - more reliable technology/longer lasting - uses much less power/more efficient
Describe two benefits of using USB connections between a computer and a device. [2]
- impossible to connect device incorrectly/connector only fits one way - has become the industry standard
A security light is controlled by sensors and a microprocessor. Describe how the sensors and microprocessor interact to switch on the security light when an intruder is detected. [6]
- infrared / motion / pressure (sensor) // sensor detects movement/pressure - signals/data sent (continuously) to microprocessor - converted from analogue to digital (using ADC) - microprocessor compares value with those stored in memory - if sensor value does not match the stored value(s) ... - ... signal sent to switch on the light - ... signal sent to keep the light on - ... light remains on for a period of time (30 seconds) - if sensor value matches the stored value(s) ... - ... light will remain off - ... will turn off after period of time (30 seconds) - works in a continues loop
Give one application of parallel data transmission [1]
- internal data transfer (buses)
Explain what is meant by phishing [2]
- legitimate-looking emails sent to a user - as soon as recipient opens/clicks on link in the email/attachment ... - ... the user is directed to a fake website (without their knowledge) - To obtain personal/financial information/data
Name three different sensors [3]
- light - temperature - pH
Solid state drives (SSD) are replacing hard disc drives (HDD) in some computers. Give three reasons why this is happening. [3]
- lower/less power consumption/more energy efficient - run cooler - run quieter - data access is faster
Explain what is meant by primary storage. Give an example [2]
- main memory inside a computer / directly accessed by CPU e.g. ROM / RAM
Explain what is meant by pharming [2]
- malicious code/software installed on a user's hard drive/actual web server - this code redirects user to a fake website (without their knowledge) - to obtain personal/financial information/data
Give one benefit of serial data transmission [1]
- more accurate/fewer errors over a longer distance
Explain what is meant by off-line storage. Give an example [2]
- non-volatile memory that can be removed from a computer system e.g. DVD/ Blu-ray / CD / USB flash memory / removable or external HDD or SSD
Explain what is meant by secondary storage. Give an example [2]
- non-volatile/persistant memory that is accessed by a device that is part of a computer system / not directly accessed by the CPU e.g. HDD / SSD
State what is meant serial data transmission [1]
- one bit sent at a time - over a single wire
Explain what is meant by virus [2]
- program/software that replicates/copies itself - can delete or alter files/data stored on a computer - can make the computer "crash"/run slow
Give four benefits of using LED technology. [4]
- reaches maximum brightness quickly - colours are vivid - good colour definition/contrast can be achieved - screens can be thinner/thin - more reliable as LED's are long lasting - consume very little/less energy
An alarm clock is controlled by a microprocessor. It uses the 24 hour clock. The hour is represented by an 8-bit register, A, and the number of minutes is represented by another 8-bit register, B. Two 8-bit registers, C and D, are used to represent the hours and minutes of the alarm time. Describe how the microprocessor can determine when to sound the clock alarm. [3]
- reads values in registers "C" and "D" - and checks the values against those stored in registers "A" and "B" - If values in corresponding registers are the same - the microprocessor sends a signal to sound alarm/ring
Automatic doors in a building are controlled by the use of infrared sensors and a microprocessor. Describe how the sensors and the microprocessor are used to automatically open a door as a person approaches. [4]
- sensor(s) sends signal/data to microprocessor - signal/data converted to digital (using an ADC) - microprocessor compares signal/data with pre-set/stored value - if sensor(s) signal/data indicates the presence of a person / the door needs to be opened / a match is found / door is closed ... - ... microprocessor sends a signal to an actuator ... - ... to operate/drive a motor to open the door
Draw the symbol for an XOR gate and explain the function of this logic gate. [5]
- similar to an OR gate - It has (at least) two inputs - Output will be high/1 if both inputs are different - Output will be high/1 if either input is high - Output will be low/0 if both inputs are high - Output will be low/0 if both inputs are low
An online bank requires a client to supply an 8-digit code each time they wish to access their account on the bank's website. Rather than ask the client to use a keyboard, they are requested to use an on-screen keypad (shown on the right) to input the 8-digit code. The position of the digits on the keypad can change each time the website is visited. The client uses a mouse or touch screen to select each of the 8 digits. Explain why the bank has chosen to use this method of entering the 8 digits. [2]
- spyware/key logging software can only pick up key presses - using mouse/touchscreen means no key presses to log - the numbers on the key pad are in random/non-standard format, which makes it more difficult to interpret
Explain why it is more secure to use drop-down boxes rather than entering characters using a keyboard. [2]
- to protect against key logging software/spyware - can stop key presses being recorded - drop down boxes can be placed in different location on the screen each time (to overcome screen capture issues)
State what is meant by the term USB. [1]
- universal serial bus
State how it is possible for a user to know that a website is secure by looking at the web address. [1]
- use of https
The LCD (liquid crystal display) on the clock face is back-lit using blue LEDs (light emitting diodes). The brightness of the clock face is determined by the level of light in the room. The amount of light given out by the LEDs is controlled by a control circuit. Describe how the sensor, microprocessor and LEDs are used to maintain the correct brightness of the clock face. [3]
- uses a light sensor - sends signal/data back to microprocessor - signal/data converted to digital (using ADC) - value compared by microprocessor with pre-set/stored value - if value < stored value, signal sent by microprocessor ... - ... to the voltage supply (unit) - ... "value" of signal determines voltage supplied/brightness of LED
Match the questions to the answers 1. What is the denary (base 10) equivalent to the hexadecimal digit E? 2. If 1 GB = 2x then what is the value of X? 3. How many bits are there in one byte? 4. If the broadband data download rate is 40 megabits per second, how many seconds will it take to download a 60 MB file? 5. What is the denary (base 10) value of the binary number 0 0 1 0 0 1 0 0 ? 6. What hexadecimal value is obtained when the two hexadecimal digits C and D are added together? Answers: 8, 12, 14, 19, 30, 36 [5]
1. 14 2. 30 3. 8 4. 12 5. 36 6. 19
Match the components to the descriptions Components: Arithmetic Logic Unit, buses, Control Unit, Immediate Access Store, Input/Output, registers Description: 1. Used to connect together the internal components of the CPU. 2. Used to carry out calculations on data. 3. Used to temporarily hold data and instructions during processing. 4. Used to allow interaction with the computer. 5. Used to hold data and instructions before they are processed. 6. Used to manage the flow of data through the CPU. [5]
1. Buses 2. Arithmetic Logic Unit 3. Registers 4. Input/Output 5. Immediate Access Store 6. Control Unit
Which descriptions correspond to compilers, and which to interpreters? 1. It is more difficult to debug the code since one error can produce many other associated errors. 2. The speed of execution of program loops is slower. 3. It produces fast, executable code that runs directly on the processor. 4. It is easier to debug the code since an error is displayed as soon as it is found.
1. Compiler 2. Interpreter 3. Compiler 4. Interpreter
Match the buses to the descriptions Buses: address bus, control bus, data bus 1. this bus carries signals used to coordinate the computer's activities 2. this bi-directional bus is used to exchange data between processor, memory and input/ output devices 3. this uni-directional bus carries signals relating to memory addresses between processor and memory [2]
1. Control 2. Data 3. Address
The URL for the music company's website is: https://www.rockict.net/index.htm Identify what part 1 and 2 represent in this URL [2]
1. Domain (name) 2. File name/webpage name
Which of the following statements apply to simplex data transmission, half-duplex data transmission and duplex data transmission? 1. Multiple bits are sent and received at the same time 2. Bits are sent one at a time in a single direction. 3. Bits are sent using a single wire. Data can be sent or received, but not at the same time. [3]
1. Duplex 2. Simplex 3. Half-duplex
Five statements about serial half-duplex data transmission are shown below. Mark the statements as true or false: 1. Data is transmitted in one direction only, one bit at a time. 2. Data is transmitted in both directions, multiple bits at a time. 3. Data is transmitted in one direction only, multiple bits at a time. 4. Data is transmitted in both directions, but only one direction at a time. Data is transmitted one bit at a time. 5. Data is transmitted in both directions, but only one direction at a time. Data is transmitted multiple bits at a time. [5]
1. False 2. False 3. False 4. True 5. False
Mark these statements as true or false: 1. 47KB is larger than 10MB. 2. 250 bytes is smaller than 0.5MB. 3. 50GB is larger than 100MB. 4. 1TB is smaller than 4GB. [4]
1. False 2. True 3. True 4. False
Match the sensors to their applications Sensors: Light, Moisture, Gas, pH, Pressure 1. Monitor the pollution levels in a river 2. Control the switching off and on of street lights 3. Detect intruders breaking into a building 4. Monitor the amount of water left in clothes in a dryer 5. Monitor acidity levels in the soil in a greenhouse [4]
1. Gas 2. Light 3. Pressure 4. Moisture 5. pH - 5
Which descriptions do the following security issues match? Security Issues: Pharming, Phishing, Viruses, Hacking, Spyware, Cookies Description: 1. illegal access to a computer system without the owner's consent or knowledge 2. software that gathers information by monitoring key presses on a user's keyboard; the data is sent back to the originator of the software 3. malicious code installed on the hard drive of a user's computer or on a web server; this code will re-direct the user to a fake website without the user's knowledge 4. creator of code sends out a legitimate-looking email in the hope of gathering personal and financial information from the recipient; it requires the user to click on the link in the email or attachment 5. a message given to a web browser by a web server; it is stored in a text file; the message is then sent back to the server each time the browser requests a page from the server 6. program or code that replicates itself; designed to amend, delete or copy data or files on a user's computer; often causes the computer to crash or run slowly [5]
1. Hacking 2. Spyware 3. Pharming 4. Phishing 5. Cookies 6. Viruses
Match the components to their descriptions. Components: Immediate access store, register, control unit, accumulator, arithmetic logic unit, bus Descriptions: 1. Holds data and instructions when they are loaded from main memory and are waiting to be processed. 2. Holds data temporarily that is currently being used in a calculation. 3. Holds data or instructions temporarily when they are being processed. 4. Manages the flow of data and interaction between the components of the processor. 5. Carries out the calculations on data. 6. Pathway for transmitting data and instructions. [5]
1. Immediate access store 2. Accumulator 3. Register 4. Control unit 5. Arithmetic logic unit 6. Bus
Which statements apply to interpreters, and which to compilers? 1. takes one statement at a time and executes it 2. generates an error report at the end of translation of the whole program 3. stops the translation process as soon as the first error is encountered 4. slow speed of execution of program loops 5. translates the entire program in one go [5]
1. Interpreter 2. Compiler 3. Interpreter 4. Interpreter 5. Compiler
Match the term to their descriptions Terms: browser, HTML, internet service provider, interrupt, IP address, MAC address Descriptions: 1. Signal sent to a processor which may cause a break in execution of the current routine, according to priorities 2. Company that provides individual's access to the Internet and other services such as web hosting and emails 3. Software application used to locate, retrieve and display content on the World Wide Web e.g. web pages, videos and other files 4. Hardware identification number that uniquely identifies each device on a network; it is manufactured into every network card and cannot be altered 5. Authoring language used to create documents on the World Wide Web; uses tags and attributes 6. Location of a given computer/device on a network; can be a static or dynamic value [5]
1. Interrupt 2. Internet service provider 3. Browser 4. MAC address 5. HTML 6. IP address
Which of the following statements apply to serial data transmission and parallel data transmission? 1. Multiple bits are sent and received at the same time 2. Bits are sent one at a time in a single direction. 3. Bits are sent using a single wire. Data can be sent or received, but not at the same time. [3]
1. Parallel 2. Serial 3. Serial
Match the 5 computer terms to 5 of the 7 descriptions Computer terms: Serial simplex data transmission, parallel half-duplex data transmission, parity check, automatic repeat request (ARQ), checksum 1. Several bits of data sent down several wires, in both directions, but not at the same time 2. Several bits of data sent down several wires, in both directions, at the same time 3. An even or odd number of bits set to 1 in a byte, used to check if the byte has been transmitted correctly 4. One bit sent at a time, over a single wire in one direction only 5. An additional digit placed at the end of a number to check if the number has been entered correctly 6. A value transmitted at the end of a block of data; it is calculated using the other elements in the data stream and is used to check for transmission errors 7. An error detection method that uses response and time out when transmitting data; if a response is not sent back to the sender in an agreed amount of time, then the data is re-sent [5]
1. Parallel half-duplex data transmission 3. Parity check 4. Serial simplex data transmission 6. Checksum 7. Automatic repeat request (ARQ)
http://www.cie.org.uk/index.htm Identify the three parts that make up this URL.
1. Protocol 2. Domain 3. Filename
Which statements are true and which are false? 1. Assembly language uses mnemonic codes. 2. Assembly language programs do not need a translator to be executed. 3. Assembly language is a low-level programming language. 4. Assembly language is specific to the computer hardware. 5. Assembly language is machine code. 6. Assembly language is often used to create drivers for hardware.
1. True 2. False 3. True 4. True 5. False 6. True
Identify and describe the purpose of two different buses. [6]
Address: - Carries / transports an address / location ... - ... of the next item to be fetched - Data travels one way (unidirectional) Data: - Carries / transports data / example of data ... - ... that is currently being processed // that will be / has been processed - Data can travel in both directions (bidirectional) Control: - Carries / transports signals - Control / directs the actions of the CPU / processor - Can be either Unidirectional or Bidirectional
Three programmers are working on different projects: • Alice is developing a program written in a low-level language • Akbar is developing a program written in a high-level language • Alex is preparing a program written in a high-level language for sale State, with reasons, which type of translator each programmer should use. Each programmer should be using a different type of translator. [6]
Alice: - Assembler - translates low level language into machine code / only option for low-level language programs Akbar: - Interpreter - easy to identify where an error is / to debug a program Alex: - Compiler - once translated a stand-alone program file is created / no need for the compiler when running the program
Name and describe a measure that the bank could introduce to improve the security of their website. [2]
Anti-virus: - removes/warns of a potential virus threat which can't be passed on to customers Firewall: - (helps) to protect bank computers from virus threats and hacking
A program written in a high-level language is translated into machine code. This is so that it can be processed by a computer. Name one type of translator that can be used [1] Describe how your answer to this translates this program. [3]
Compiler: - Translates the whole program as a complete unit / at once - Creates an executable file / object code - A report / list of errors in the code is created - Optimises the source code (to run efficiently) Interpreter: - Translates a program one line of code at a time - Machine code is directly executed // The interpreter is used each time the program / code is executed - Will identify an error as soon as it finds one in a line of code
Name the security issue described by this statement: A small file sent by a web server to a web browser; every time the user visits the website, data about user preferences is collected [1]
Cookies
Name the security issue described by this statement: The act of illegally changing the source code of a program so that it can be exploited for another use [1]
Cracking
Which of the following features apply to DVD-RW, DVD-RAM, CD-ROM and Blu-ray discs? - Single track - Many concentric tracks - Blue laser used to read/write data - Red laser used to read/write data [4]
DVD-RW: Single track, Red laser DVD-RAM: Many concentric tracks, Red laser CD-ROM: Single track, Red laser Blu-ray disc: Single track, Blue laser
Name the security issue described by this statement: The act of gaining unauthorised access to a computer system [1]
Hacking
Give the meaning of HTML [1]
HyperText Markup Language / language used to create web pages
A set of photographs has been taken for a wedding. All the guests are to be sent digitally stored copies through the ordinary postal service. There are fifty photographs and each photograph is between 1.8 and 2.5 megabytes in size. Work out the maximum storage space required for a set of photographs. State, with a reason, a suitable medium to use for the copies to be sent to the guests. [3]
Max storage space: 125 megabytes Medium: CD / low capacity flash memory Reason: good for mailing / inexpensive to buy
A washing machine has a small display screen built into it. One use of the display screen is to show an error code when a problem has occurred with a washing cycle. State whether the display screen is an input, output or storage device. [1]
Output
Name the security issue described by this statement: Malicious code installed on a user's hard drive or a web server which redirects the user to a fake website without their knowledge [1]
Pharming
A company has a number of offices on one site. Data are transmitted, using a wired network, from one office and stored at another office. State, with reasons, which data transmission, serial or parallel, should be used [3]
Serial: - serial data transmission more reliable over distance - it is a cheaper connection as only single wire needed
Identify three sensors that could be used in the washing machine. State what each sensor could be used for. [6]
Temperature (sensor): - To monitor the temperature of the water Motion (sensor): - To monitor whether the drum is still in motion pH (sensor): - To monitor the level of water hardness/detergent present in the water
The processes in a chemical factory are monitored by sensors connected to a microprocessor. Identify two different sensors used in this application. Give an example of how each sensor could be used in the chemical factory. [4]
Temperature (sensor): - to measure the temperature of the chemicals to make sure it is not too high/low pH (sensor): - to measure the pH to make sure the acidity / alkalinity of the chemicals is correct
Name the security issue described by this statement: Program code that can replicate itself with the intention of deleting or corrupting files stored in a computer [1]
Virus
The seven stages in a von Neumann fetch-execute cycle are shown in the table below. Put each stage in the correct sequence. The first one has been done for you. a. the PC (program counter) contains the address of the next instruction to be fetched 1. the instruction is then copied from the memory location contained in the MAR (memory address register) and is placed in the MDR (memory data register) 2. the instruction is finally decoded and is then executed 3. the entire instruction is then copied from the MDR (memory data register) and placed in the CIR (current instruction register) 4. the address contained in the PC (program counter) is copied to the MAR (memory address register) via the address bus 5. the address part of the instruction, if any, is placed in the MAR (memory address register) 6. the value in the PC (program counter) is then incremented so that it points to the next instruction to be fetched [6]
a, 4, 1, 3, 5, 2, 6
Give the meaning of http [1]
hypertext transfer protocol / protocol used by web browsers
Give the meaning of https [1]
hypertext transfer protocol secure / secure protocol used by web browsers
Nikita wishes to print out some documents and connects her printer to the computer using one of the USB ports. Identify what type of data transmission is being used. [1]
serial
Describe what is meant by https. [2]
− Hypertext Transfer Protocol Secure // it is the access protocol // It is a protocol − It means data sent (to and from the webserver) is encrypted
Explain what is meant by off-line storage [2]
− Non-volatile storage − Off-line storage is storage that is removable from a computer/device // not internal // portable − An example of off-line storage would be CD/DVD/USB stick/SD card/magnetic tape/ external HDD/SSD
Explain what is meant by secondary storage [2]
− Not directly accessed by the CPU − Non-volatile storage − An example of secondary storage would be HDD/SSD
Describe what is meant by HTML structure and presentation for a web page. [4]
− Structure and presentation are defined using (mark-up) tags − Structure is used for layout − Presentation is used for formatting / style − Separate file / CSS can be used for presentation content
A business wants to use a biometric security system to control entry to the office. The system will use a biometric device and a microprocessor. Explain how the biometric security system will make use of the biometric device and the microprocessor to control entry to the office. [6]
− Suitable biometric device, such as fingerprint scanner/retina/eye/iris scanner/face recognition/voice recognition/palm scanner // description of use e.g. use fingerprint on device − Sensor (in biometric device) captures/takes data/readings (of user) − Data/readings are converted from analogue to digital (using ADC) − Data/reading sent to the microprocessor − Data/readings compared to stored values/data ... − ... if data/readings match user can enter − ... if data/readings do not match user is declined entry // user asked to try again ... − ... alert may be sent to security // alarm may sound
Describe how a compiler translates a computer program. [3]
− Translates high-level language into machine code/low level language − Translates (the source code) all in one go/all at once − Produces an executable file − Produces an error report