Comptia A+ Core 1 -- Section 3

LCD (Liquid Crystal Display)

• Display Technology - Requires a backlight

  • Has a lower contrast ratio than the alternative

  • Most common in modern displays

TN (Twisted Nematic)

• LCD Display Technology

  • Very old

  • Bad viewing angle

  • Bad color

  • High refresh rate

IPS (In-Plane Switching)

• LCD Display Technology

  • Great color

  • Good viewing angles

  • Decent refresh rate

VA (Vertical Alignment)

• LCD Display Technology

  • Great color

  • Not-so-great refresh rate

OLED (Organic Light-Emitting Diode)

• Display Technology — DOESN’T require a backlight

  • Better contrast ratio with deeper blacks

  • Used in most smaller devices

  • Can suffer from “burn in”

Inverter

• Converts DC to AC for the backlight

(*Often the cause of “flickering” or screen dimness)

Screen Resolution

• The total number of individual dots (pixels) making up an image on a screen

Pixel Density

• How tightly pixels are packed together, measured in PPI (Pixels Per Inch)

Color Gamut

• The range of colors a display can produce

Copper Cable

Cable:

• Speeds up to 40 Gbps

• 1100 m

Fiber Cable

Cable:

• Speeds up to 100+ Gbps

• 40 km

Attenuation

• The loss of signal strength in networking cables or connections

EMI (Electro Magnetic Interference)

• A condition when signals from a device or cable leak out and disrupt signals of another device or cable

Twisted Pair Cable

• Cables consisting of 8 wires that are twisted into pairs

RJ11

Cable Connector:

• 4 pin

• used in modems and dial up phones

RJ45

Cable Connector:

• 8 pin

• found in computer networks

Cat 5

Cable Type:

• 100 Mbps

• 100 m

• Used in older networks

Cat 5e

Cable Type:

• 1,000 Mbps / 1 Gbps

• 100 m

• More twist per foot allows it to handle disturbances to achieve faster speeds

Cat 6

Cable Type:

• 10,000 Mbps / 10 Gbps
  1,000 / 1 Gbps

• 55 m
  100m

• Plastic separates the 4 wire pairs which minimizes crosstalk

Cat 6a

Cable Type:

• 10,000 Mbps / 10 Gbps

• 100 m

• thicker wires carry more powerful signals for longer distances

Wiring Standards

• T568 A

• T568 B orange and green cables switch position

RG - 6
F connector

• Common coaxil cable & connector