OSI Model
What does OSI stand for?
Open Systems Interconnection
What is the main job of the Physical Layer?
To send raw bits (0s and 1s) over a physical medium
What type of media uses electricity to send data?
Copper cables (like Ethernet)
What hardware connects a computer to a network?
Network Interface Card (NIC)
What are the two values of a bit?
0 and 1
How many layers are in the OSI Model?
7 layers
Does the Physical Layer understand the meaning of data?
No it only moves bits
What type of cable uses light to send data?
Fiber optic cable
What device sends data to all connected devices without filtering?
A hub
How is a “1” usually shown in an electrical signal?
High voltage
Which OSI layer is the Physical Layer?
Layer 1
What type of data does the Physical Layer work with?
Raw bits (0s and 1s)
Which physical media sends data through the air?
Wireless (radio waves)
What device boosts or strengthens weak signals?
A repeater
How is data represented in fiber optic cables?
Light pulses (on and off)
Why is the OSI Model useful?
It helps organize how networks work and makes troubleshooting easier
What three things can represent bits at the Physical Layer?
Electrical signals, light pulses, and radio waves
Which media type is usually the fastest?
Fiber optic cables
Is a modem part of the Physical Layer?
Yes
What does the Physical Layer define about signals?
Voltage levels, timing, and signal type
What happens to network communication if Layer 1 fails?
No data can be sent at all
Why is the Physical Layer considered the foundation of networking?
Because all other layers depend on it to physically send data
Name one advantage and one disadvantage of wireless media.
Advantage: No cables needed
Disadvantage: Can be slower
Name two Physical Layer devices.
NIC, hub, repeater, modem, cables
Why must the sender and receiver agree on signal timing?
So the bits are read correctly