IPA IP 2022 Question 97
A question IPA Japan published in 令和4年度 ITパスポート試験 公開問題 問97, translated into English. ITPEC is based on the same exams.
Same question on ITPEC: Oct 2025 Q13 +1 more
There is an IoT system that automatically opens and closes the water gate for a rice field by measuring the water level in the rice field. Which of the following is the appropriate combination of terms to be inserted into blanks A and B in the figure?
Explanation
A: Sensor, B: Actuator — A turns the water level into data, B turns the server's instruction into movement of the gate.
Follow the arrows through the IoT device:
- •Water level → A → communications module → server: A measures a physical quantity and turns it into an electrical signal, which is a sensor
- •Server → communications module → B → water gate: B receives the instruction and physically opens or closes the gate, which is an actuator (a motor, for example)
Answer (d)
Why not others:
- •(a) — an actuator does not measure anything, and B drives the gate rather than relaying data
- •(b) — swaps the two: an actuator cannot read the water level, and a sensor cannot move the gate
- •(c) — A is right, but an IoT gateway relays data between devices and a network or server; that job is already done by the communications function module, and a gateway moves no gate
Key rule: In a control loop a sensor converts the physical world into data (input), and an actuator converts a control signal 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.