Which OSI layer is responsible for transmitting raw bits over a physical medium?

Which OSI layer is responsible for transmitting raw bits over a physical medium?

• A. Physical layer
• B. Data Link layer
• C. Network layer
• D. Application layer

Answer: (A)

Transmitting raw bits over a physical medium is the job of the physical layer. This layer defines how bits are represented as electrical or optical signals, how devices connect to the medium, and how timing and synchronization occur at the bit level. It operates without interpreting or organizing the data, focusing solely on the physical transmission itself. Higher layers take over from there: the data link layer adds framing and error detection and manages access to the medium; the network layer handles routing; the application layer deals with user-facing communication. So the physical layer is responsible for the raw bit transmission.

Transmitting raw bits over a physical medium is the job of the physical layer. This layer defines how bits are represented as electrical or optical signals, how devices connect to the medium, and how timing and synchronization occur at the bit level. It operates without interpreting or organizing the data, focusing solely on the physical transmission itself. Higher layers take over from there: the data link layer adds framing and error detection and manages access to the medium; the network layer handles routing; the application layer deals with user-facing communication. So the physical layer is responsible for the raw bit transmission.