Mobile Devices (1.2, 1.3 and 1.4)

Question 1

How does a capacitive touch screen work?

Answer 1

It sees the distortion in an electrostatic field

Question 2

What happens when the application of voltage is changed for an LCD?

Answer 2

The properties can change

Question 3

Define a pixel

Answer 3

An individual point on a screen inside of a display

Question 4

What is a thin-film transistor (TFT) referred to as?

Answer 4

An LCD panel.

Question 5

How does twisted nematic work?

Answer 5

Crystals twist or untwist in response to the voltage being applied or removed. It supports fast response time in comparison to other TFT technologies and displays.

Question 6

How does in-plane switching work?

Answer 6

Crystals rotate to be able to deliver colour.

Question 7

What viewing angles can IPS support?

Answer 7

178 degrees horizontal and vertical

Question 8

How does vertical alignment work?

Answer 8

Crystals are tilted to be able to deliver colour.

Question 9

How much better is the contrast ratio for VA than a standard IPS display?

Answer 9

Two to three times better.

Question 10

How does cold cathode fluorescent lamp work?

Answer 10

A lamp sits behind the display and lights up the LCD to show the colours and images properly on the screen. It requires AC voltage.

Question 11

How do LEDs work?

Answer 11

They are a form of light that use DC.

Question 12

How do OLEDs work?

Answer 12

Each pixel has its own seperate LED that provides the light; they can be made from plastic. They can also be folded, rolled, or manipulated to create different display shapes and sizes.

Question 13

What is a digitiser (phone-specific)?

Answer 13

A layer sandwiched between a layer of protective glass and the display panel inside a touchscreen display

Question 14

What is the purpose of the digitiser?

Answer 14

It uses haptic feedback to provide a form of touch responsiveness from the display back to the end user

Question 15

What is an accelerometer?

Answer 15

A combination device that uses hardware and software to measure the velocity, rotation, and shaking of a mobile device. It uses the x and y axis.

Question 16

What is a gyroscope?

Answer 16

An improved version of the basic accelerometer

Question 17

Name three things the gyroscope does.

Answer 17

• Detects pitch (y), roll (x), and yaw (z)
• Performs actions
• Stabilises images

Question 18

Which devices have faster and/or stronger wireless speeds, and why?

Answer 18

Larger devices, because they have larger antennas so pick up signals with more strength and faster speeds

Question 19

What does the Global System for Mobile Communication (GSM) do?

Answer 19

Takes the voice during a call and converts it into a digital format

Question 20

Name the two types of code-division multiple access (CDMA).

Answer 20

• Wideband CDMA (W-CDMA)
• Universal Mobile Telecommunications System (UMTS)

Question 21

How does CDMA work?

Answer 21

It uses code division to split up the channel; is more powerful and flexible than GSM.

Question 22

What is the preferred roaming list (PRL)?

Answer 22

A list containing all the information about different cellular towers; restrictions vary between models and the device’s country of origin

Question 23

Describe the form factor of the DB9 connector.

Answer 23

D-shaped, 9 pins.

Question 24

What is the name for the device that allows you to connect to another device and get information from it?

Answer 24

Universal Asynchronous Receiver-Transmitter (UART)

Question 25

What are some features of the USB-C cable?

Answer 25

Modern version of USB, operates at USB 3.0 speeds and can provide data

Question 26

Contrast a port replicator with a docking station.

Answer 26

Port replicators use the exact same features as a laptop (port mirror) whereas docking stations provide additional ports.