Which metric describes the time it takes to locate data on a disk?

• A. Rotation speed
• B. Average access time
• C. Data transfer rate
• D. Cache size

Answer: (B)

The time to locate data on a disk is described by average access time. This metric captures the total latency from a read request to when the data actually starts being read, incorporating the seek time to move the head to the correct track and the rotational latency as the disk spins to the right sector (often with transfer time included as data begins to move). The other terms describe different aspects: rotation speed affects how quickly the disk spins (influencing latency but not a direct measure of locate time), data transfer rate measures how fast data moves once located, and cache size pertains to how much data can be kept in fast memory, which can affect overall performance but not the specific time to locate data.