IPA IP 2021 Question 72
A question IPA Japan published in 令和3年度 ITパスポート試験 公開問題 問72, translated into English. ITPEC is based on the same exams.
There is a system that consists of IoT devices and an IoT server, in which an IoT device sends the outside air temperature that it measured to the IoT server, and the IoT device opens and closes a window by following instructions from the IoT server. Which of the following is installed in the IoT device of this system and has the role of opening and closing the window?
Explanation
Actuator — the component that turns an electrical signal into physical movement, here opening and closing the window.
The system works as a loop. A sensor in the IoT device measures the outside air temperature and turns it into an electrical signal, and the device sends the value to the IoT server. The server decides what to do and sends back an instruction. The IoT device then has to act on the physical world: the actuator, such as a motor, receives the instruction as an electrical signal and moves the window open or shut.
Answer (a)
Why not others:
- •(b) Edge computing — processing data on or near the device instead of on a distant server; a way of placing processing, not a part that moves anything
- •(c) Carrier aggregation — a mobile-communication technique that bundles several frequency bands to raise the transmission speed
- •(d) Sensor — the part that measures the outside air temperature; it converts a physical quantity into an electrical signal, the opposite direction from opening a window
Key rule: A sensor turns the physical world into signals (input); an actuator turns signals into physical action (output).
Hardware · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.