Test 1 Flashcards
Conductor
Type of material that allows the flow of electrical current
Insulator
Type of material that does not allow free electrical flow. Ex: glass, wood, plastic
Generator
Device that converts mechanical energy into electrical energy
Motor
Device that converts electrical energy into mechanical energy
Voltage
Has the potential to move electrical charge (pressure). Ex: water tower and gravity. Measured in volts
Resistance
Opposition to current flow. Higher the resistance, the lower the current. Measured in Ohms
Current
The actual flow of electrons. Measured in Amps.
Circuit
The loop of electricity that must be closed
Ohm’s Law
Voltage = Current x Resistance (E=IR)
Alternating current (AC)
Constantly changes polarity
Direct current (DC)
Flows in one direction
Electricity
The movement of electrons
Structured cabling types: horizontal & Cat5 cabling
Uses unshielded twisted pair (Cat5 has 4 pairs), patch panels, jacks, and plugs. Cat5 are twisted to prevent radiomagnetic interference
Patch panel
Allows Cat5 cables to be more permanent in a network; cheaper fixes
Punch-down tool
Use to connect Cat5 to a patch panel
Jack
Connection socket
Fiber optic cabling: multimode and singlemode
Uses frequencies of light to transmit data; no electricity = no interference; uses glass or plastic to reflect light; Multimode is used for short distances, cheaper, slower, laser or LED; singlemode is more expensive, long distances, faster, laser only
Fiber optic connector
Always in pairs because signal can only go one way rather than both
Network
A system of 2 or more computing devices connected by a shard medium using communication software
LAN
Local area network
MAN
Metropolitan area network
WAN
Wide area network
Circuit switching
Original system, invented by Alexander G Bell; Plain old telephone system
Packet switching
Ethernet and internet; new system
