4 Hardware Flashcards
Which are the 3 type of touchscreens used in devices like tablets?
- The resistive touchscreen, which is the cheapest method however, it can be easily damaged.
- The capacitive touchscreen, which uses conductive strips and is a stronger touchscreen than resistive.
- Infra-red screen which is the most punctual screen.
What does QR stand for?
Quick response code and it is mostly used by companies to track down the location of the products in the factories.
EPOS terminal
Electronic Point of sale - it works out the cost of the shopping.
What does 3D mean?
It means three dimensional.
OMR
OMR stands for optical mark recognition - it is mainly used to see marks on worksheets(test papers).
The types of sensors.
Light sensor Temperature sensor Pressure sensor Magnetism sensor Moisture sensor Humidity sensor Acidity (pH) sensor Motion sensor
What are the two types of printers
Ink Jet and Laser.
What is an actuator?
An actuator is any motor that moves an object around.
What is a servomechanism?
A servomechanism is a machine that uses feedback to regulate motion.
What does CAD and CAM stand for?
CAM stands for computer aided design
CAD stands for computer aided manufacturers.
How much storage does a 1 minute CD take up?
10 MB.
What are sensors
Sensors are automatic input devices and a sensor is a device that senses physical changes in a particular area
Types of sensors
Light sensors - detect the amount of light from in an area. Digital camera or scanner
Temperature sensor - detect the change and in the temperature. Cooker
Pressure sensor - senses if it collides with another object. Robotic vacuum cleaner.
Magnetism sensor - used in compasses mostly to see where is north and where is south.
Moisture and humidity sensor - detect water or vapor. Used in greenhouses to monitor the humidity of the ground.
Acidity sensor - it measures the pH of a substance. Mostly used for medical purposes.
Motion sensors - detect a movement for example by Infra-red lights. Used in burglar alarms or for computer games.
The cycle of control systems
Input - process - output - feedback
An example of a control system
A bread oven does this. When you put a bread inside it (input). It heats the bread when the oven is too hot (output) it cool it down (feedback). And it does this over and over again.
How does an LCD monitor work? What does it stand for?
It stands for liquid crystal display because it holds a liquid crystal layer between transparent sheets.
What are LED and what do they stand for?
LED stands for light-emitting diode and they are really little light bulbs only they use less electricity and emit less heat
What does OLED stand for and why?
It stands for organic LED because it is even smaller than a normal LED and it is more expensive
The two common projector types.
Digital light projector (DLP) - a beam of light passes through the LCD and then onto the wall.
LCD projector- works by shining a light onto a grid of thousands of tiny mirrors.
What are sensors
Sensors are automatic input devices and a sensor is a device that senses physical changes in a particular area
The two common projector types.
LCD projector - a beam of light passes through the LCD and then onto the wall.
Digital light projector (DLP) - works by shining a light onto a grid of thousands of tiny mirrors.
What does OLED stand for and why?
It stands for organic LED because it is even smaller than a normal LED and it is more expensive
What are LED and what do they stand for?
LED stands for light-emitting diode and they are really little light bulbs only they use less electricity and emit less heat
How does an LCD monitor work? What does it stand for?
It stands for liquid crystal display because it holds a liquid crystal layer between transparent sheets.
An example of a control system
A bread oven does this. When you put a bread inside it (input). It heats the bread when the oven is too hot (output) it cool it down (feedback). And it does this over and over again.
The cycle of control systems
Input - process - output - feedback
Types of sensors
Light sensors - detect the amount of light from in an area. Digital camera or scanner
Temperature sensor - detect the change and in the temperature. Cooker
Pressure sensor - senses if it collides with another object. Robotic vacuum cleaner.
Magnetism sensor - used in compasses mostly to see where is north and where is south.
Moisture and humidity sensor - detect water or vapor. Used in greenhouses to monitor the humidity of the ground.
Acidity sensor - it measures the pH of a substance. Mostly used for medical purposes.
Motion sensors - detect a movement for example by Infra-red lights. Used in burglar alarms or for computer games.
How many bits are needed to store one ASCII character? How about Unicode character?
1 byte for ASCII
4 byte for UNICODE
How do you calculate the size of a picture?
Multiply the no of pixels with the number of bits needed to store the picture (1, 4, 8, 24 bit)
What is a bitrate?
No bits needed to store one second of sound.
What does bit deph mean?
- In case of pictures it meas the number of bits needed to store data about one pixel (monochrome, 256 color, 167 million color, 16 color)
- In case of a sound it means the number of bits needed to save one second of sound. Bit depth can be modified by modifying the number of higher and lower sounds.
What kind of storage do you know?
Primary(RAM), Secondary (HDD, SDD, stick, card)
Secondary storage can be in the computer or offline(portable hard disk, stick, SD card)
How CD stores data?
A CD stores data by having small pits or marks in a spiral pattern.
Type of CD-s from read-write point of view.
Read only
Write once
RW (Rewritable)
