Unit 1 Flashcards
What does desktops need to connect with?
Peripheral devices
Does laptop need peripheral devices?
No
What makes laptops portable?
Components are connected as one piece, and it doesn’t need peripheral devices and it has small size and low weight which makes it portable.
What are single board computers?
Single board computers are affordable computers which are used in education embedded and physical computing projects.
What do mobile phones use to connect to mobile network?
SIM card
What is SIM card for?
Subscriber identity module, which identify the subscriber to the mobile network.
What are smartphones?
Smartphones are small computers with WIFI and connectivity which allows users to make phone calls and access to the internet.
What does smartphone use to enter text, numbers and other characters?
Virtual keyboard
What are tablets?
Tablets are much bigger version of phone with similar features
What does digital cameras can camcorders use to capture image?
they use light sensors to capture images formed by light passing through the lens of the devices.
What does the quality of image depend on?
It depends on the quality of lens, image processor and sensor’s resolution.
better quality lens allow light to travel through without any defects
Better image processor can compensate poor lighting conditions
Better quality sensors can capture more details
What does the quality of image is set by in television?
numbers of pixels known as screens’ resolution.
What is the format of screen’s resolution of television?
Horizontal pixels x vertical pixels
What do sound systems produce?
Sound systems produce loud rich sounds using good quality speaker and amplifiers.
What is personal video recorders?
They are used to record the broadcasted content to watch it later date.
What are Blu-ray and DVD players?
Blu rays and DVD players are connected to television to play films and contents stored in the DVDs and Blu rays disks.
What are game consoles use to?
Games consoles enable users to play games on television screen.
What does handheld versions of games consoles provide?
It provide user with mobile gaming
What does media players provide?
Media players allow to stream video and audio contents directly from the internet or local storage to the television.
What is the function of navigation aids?
It can calculate the best routes between 2 or more locations, can provide updates to the route if it is not followed accurately.
What does navigation use to determine the location of the devices on earth?
It use information from GPS satellites.
What is GPS?
Global positioning system which use radio signals from satellites to navigate the exact location of user on earth on special piece of equipment.
What is multifunctional device?
Device than can perform range of different functions.
What is convergence?
When the design of devices change to become similar to one another.
What does convergence do?
Blurs the distinction between different types of devices.
What does portability of a device depend on?
Weight and size of the device
Which carry out software instructions?
Processor
What is processor?
One or more CPU to carry out software instructions
Which allow instructions to be loaded into the processor?
RAM
What is Ram and virtual memory?
Random access memory - memory used by computer system to run software.
Virtual memory - memory used by processor once the space in the RAM has ran out.
What are files and program?
Files = collection of date that represents the document, image and data base.
program = set of instructions carried out by the processor
What is user interface?
the system which allows user to interact with the device
What are the features of command line interface and menu driven interface?
In command line interface:
- users have to type a precise text instruction as an input for computer
- system display output result as text
- it requires less memory.
Menu drive interface
- display a set of instructions which user can click to run a command or go to further menu options.
- They are easier to use than CLI
- But it can be tedious to go specific menu structure or to run a command.
What is graphical user interface is controlled by?
It is controlled by the cursor and use a screen made up of window, logo and menu.
- Window is the area of screen dedicated to the application
- Logo represents the application
- Menu are a bunch of options relating to the application
What does voice interface allow users to do and how?
Voice interface
- allow users to give spoken commands to a device
- Use voice recognition software to match spoken words with word in library to carry out instruction
Why using voice interface usually require internet?
In order to save storage, the words of library are stored on the internet
What is media?
Media are items such as memory which make information available to the users and devices.
What is backup?
Back up is making a copy of information stored in the computer in case the original is lost or damaged.
What is the advantage and disadvantage of voice interface?
Sometimes software can’t match the words and return incorrect result.
Advantage is that it allows hands free operations.
What is gesture interface?
it allows user to interact with devices by swiping fingers across screen.
How can device share data?
Devices can share date by connecting to each other using wired or wire-less connectivity.
What do different connectivity types provide?
Different connectivity types provide
- different speed of date transfer
- different level of convenience.
Although wired connectivity are usually faster and reliable, why more people tend to use wireless connectivity?
Because it results
- additional costs
- inconvenience
- safety risks.
What is one benefit of lowering energy consumption in mobile devices?
Longer battery life
What is the aim of mobile phone producers creating mobiles phones which consume less energy?
In this way
- they can help save customer’s money
- demonstrate their social responsibility.
What are some software security features?
- Users have to enter passwords or PIN in order to use the device.
- If the device is not used for certain period of time, the user has to reenter the password or pin to use it.
- If the incorrect pin is putted multiple times, it gives a set of time before trying again.
- Some devices use biometric scanners
What is more secure four-digit pattern PIN or four-digit PIN
Four-digit pattern PIN
How to prevent someone from stealing your computer?
By connecting special screw to the port on the device which is used to secure locks in place.
What are three types of peripherals devices?
Input, Output and Storage
What are input peripherals devices?
- Keyboard
- Pointing devices
- Joystick - commonly used on games
- Graphic tablet - Users use stylus to draw or write on the graphic tablet
What is shortcut?
Combination of key presses used to carry out common software command quickly.
What is pointer used for?
Pointer is onscreen indicator which used to select displayed objects
What are pointing devices?
- Mouse - used optical sensor to recognize movement of devices
- Tracker Ball
- Touchpad - sense finger movements, touches and presses
How do scanners record physical documents as images?
They use light sensor
What is OCR(Optical character Recognition) and OMR (Optional Mark Recognition)?
OCR - software that allows scanner to read characters on the document and produce the result as text file.
OMR - software that allow scanner to identify simple marks on document
What is bar code?
Bar code is a pattern of lines and gap which can be read by the bar code reader.
What are two types of barcode?
Linear and matrix
Matrix codes are also known as —–?
QR codes
How are webcams used for?
Webcams are
- used as security cameras
- use to stream images and videos on internet.
What is microphone used for?
It is used to capture sound.
What are two types of touch screen?
Resistive and capacitive
What is resistive screen and capacitive screen?
When the user presses resistive screen, the pressure makes the 2 layers underneath the screen to make connection.
When the user press capacitive screen, a small amount of charge is flow away from the fingers which device can use to track the movement.
How does biometric scanners work?
It is worked by measuring part of the unique characteristics of the user
What are some examples of biometric scanners?
Fingerprint recognition - read the patterns of arches, loops and whorls on finger print.
Facial recognition - read the structure of human face to identify an individual
Voice recognition
Iris recognition
Is iris recognition more reliable than fingerprint recognition?
Yes
What are some advantages of biometric scanners?
Easier to use than passwords as the biometric data cannot be forgotten
Faster transaction
More difficult to trick or confuse biometric scanners
Not restricted by language barriers
What are card readers used to?
They are used to read data stored on a card.
How do cards carry data?
Magnetic strip
Programmable chip
RFID
What is the least secure method of card storage?
Magnetic strip
What is specialty of programmable chip?
User need to enter pin to allows the data on the chip to be read.
What do radio frequency identification contain?
It contains ID number which is linked to records in a database.
What are sensors?
Sensors are input peripherals that inputs data about physical environment
What are the benefits of the use of sensors?
- Place in remote or dangerous place
- Monitor continually
- Remove the possibility of human error
- Sense things human can’t sense
- Convert data into digital form easily
What are factors which sensors detect?
- Light
- Moisture and humidity
- Temperature
- Proximity and distance
What do monitors do?
They allow users to see computer’s output on the electronic display.
What are three types of standard printers?
Laser
Inkjet
Dot matrix
How does dot matrix print?
The print is made by hitting or impacting the paper through a ribbon of ink.
What does inkjet printers use?
They use cartridges containing different colored ink.
What do laser printers contain?
They contain rotating cylinder or drum that holds electric charge.
How does laser is used in laser printers?
A laser is used to discharge certain points on the drum and draws the image.
What are 3d printer used to do?
They are used to create real-life versions of digital models.
What does plotter draws?
Plotter draws high quality images created in CAD software onto large sheets of paper.
Where do data projectors use?
They are used for home entertainment, watching televisions, playing games and giving presentations.
What are features of data projector?
They have Light bulbs
Resolution
Zoom functionality
Portability
What are speakers use to?
They allow computers to output sounds.
What is optical zoom and digital zoom?
Optical zoom - Focusing a lens in order to zoom in on an object
Digital zoom - enlarging part of an image to produce the effect of zooming in.
What is stereo sound and surround sound?
Stereo sound - sound that comes from two sides
Surround sound = sound that comes from four or more sides
Which sound do speakers in pair and multiple produce?
Speakers in pair - stereo sound
Multiple speakers - surround sound
What are control devices?
They are components of a system that make something happen in the real physical world.
Valves
Pistons
Heaters
Coolers
Motors
What are secondary storage?
Secondary storage are non-volatile storage that will not lose data when the system power turned off.
What are secondary storage used for?
- Storing document for future use
- Storing an application
- Virtual memory
What is virtual memory?
Space on a computer for storing instructions and programs until they are needed or being used.
What are storage devices used to?
They are used to store data or software that is used in a computer system.
What are different types of storage devices?
Internal drives are connected directly to the motherboard
External devices are connected to computer’s motherboard through different ports.
What does hard disks provide?
It provides a connection from the disk to the motherboard.
What are hard disks made up of?
They are made up of many concentric platters
What are types of optical media?
CD, DVDs and Blu-ray disks
How the data is written in CD, DVDs and Blu-ray disks?
data is written to the disk using a laser
Data is written to DVDs using shorter wavelength of red laser light.
Data is written in Blu-ray disks using violet laser light with greater density than red laser light
Can CDs and DVDs can be rewritten?
Yes
How much do CDs, DVDs and Blu-ray disks can be stored?
CD - 700 MB
DVD - 18 GB
Blu-ray disk - 50 GB
What are flash media?
Flash media is a type of secondary storage which is more energy efficient and doesn’t have moving parts
What is the fastest and slowest storage device?
Flash media - fastest
Magnetic tape - slowest
What is only portable storage device?
Flash media
Which storage device has the highest cost per GB.
Flash media
What do different storage devices use to represent 0 or 1.
Hard disk use different magnetic charge of a platter.
Magnetic tape use different magnetic charge of a tape.
Optical media use tiny bumps.
Flash media use different levels of electric charges
