Data representation
The smallest unit of an image is called a ....
Pixel
Describe serial transmission
Single bit at a time
Down a single wire
Identify one input, one storage and one output device you can find in a supermarket
Barcode scanner, keyboard
Printer, monitor
SSD / HDD
Identify the two types of software
System and application
Another name for the text based address for a website
What is the largest number that can be represented by 8 bits
255
Identify the three parts of a data packet
Payload
Trailer
Header
Identify 5 registers you can find in the CPU
MDR
CIR
PC
ACC
Managing memory
Multitasking
Managing interrupts
Providing platform for application software
Providing user interface
Describe the difference between symmetric and assymmetric encryption
Symmetric uses one key- public for encryption and decryption.
Assymmetric uses two- public and private.
Describe the difference between a sample rate and sample resolution
Sample rate- The number of samples recorded each second.
Sample resolution- The number of bits that are used to record each sound sample.
Describe the term packet switching
A method of transmitting data packets across a network. Each data packet is able to take an individual pathway across a network
ACC
What does the word portable refer to in the context of programming languages
A program that can run on different types of computers. High level language is considered portable.
Describe the features of a DDOS attack
Malware is sent
Create a botnet / bots
Perpetrator uses bots to send requests to server
Server is overwhelmed and crashes
Server is inaccessible denying service to legitimate users
Calculate the size of this file:
10 images in the file
Image resolution is 100 x 150
Colour depth is 8 bits
In bytes
1,200, 000 / 8 = 150,000 bytes
Describe how a checksum error detection method works
Uses a calculated value to check for errors
A value is calculated from the data that will be transmitted
Method such as modulus 11 is used
Once value has been calculated it is sent with the data be transmitted
Receiving device carries out the same calculation
If the values match there is no error, if the values don't match there is an error
Identify and describe the three factors that affect the performance of a CPU
Cores- More cores then the more FDE cycles that can happen at the same time
Clock speed- Measured in hertz, refers to the number of FDE cycles that can happen per second.
Cache- Memory in the CPU to store frequent instructions, less fetch cycles to the RAM
Identify four features of an IDE
Auto correction
Pretty print
Run time environment
Describe how a greenhouse would use an automated system
The temp sensor takes a reading
Reading is coverted to digital using ADC
Reading is sent to microprocessor
Reading is compared to pre stored values
If reading is out of range then the actuator would take action by opening, closing or activating an output device.
If it is in range, then nothing happens
The process is continuous.