IPA IP 2020 Question 99
A question IPA Japan published in 令和2年度 10月 ITパスポート試験 公開問題 問99, 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 a motor installed in the IoT device opens and closes a window by following instructions from the IoT server. Which of the following is an appropriate role of the actuator in this system?
Explanation
Opening and closing the window — an actuator turns an electrical signal into physical movement, here the motor that moves the window.
The system works as a loop with three kinds of part:
- •Sensor (in the IoT device) — measures the outside air temperature and turns it into an electrical signal
- •IoT server — receives the temperature data, decides, and sends opening and closing instructions back to the device
- •Actuator (the motor in the IoT device) — acts on the instruction by physically opening or closing the window
Answer (d)
Why not others:
- •(a) — receiving the temperature data is done by the IoT server
- •(b) — sending the instructions is also the IoT server's role; the actuator carries them out
- •(c) — turning a physical quantity into an electrical signal is what a sensor does, the opposite direction to an actuator
Key rule: A sensor turns the physical world into signals; an actuator (motor, valve, solenoid) turns signals back into physical action.
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.