Challenge your understanding of embedded system components with this quiz on sensors and actuators. Learn key principles, application scenarios, and how these elements interact within embedded environments for accurate data collection and control.
Which type of sensor in an embedded system is primarily responsible for converting temperature changes into measurable electrical signals, such as when monitoring engine heat?
Explanation: A thermistor is designed to sense temperature changes and convert them into electrical resistance that can be measured. A potentiometer is used for measuring position or adjusting voltage, but it does not sense temperature. An ultrasonic sensor measures distance using sound waves, not temperature. A relay is an actuator, not a sensor; it controls circuits rather than measuring heat.
If a microcontroller needs to physically move a lever in response to a sensor reading, which actuator type is typically appropriate for this task?
Explanation: A linear actuator converts electrical signals into precise linear motion, making it suitable for moving mechanical parts such as levers. A capacitive sensor measures changes in capacitance and is used for touch detection, not actuation. An accelerometer is a sensor that measures acceleration, not a device for moving objects. A humidity sensor measures moisture levels and also cannot perform any movement.
What is the main difference between analog and digital sensors used in embedded systems when detecting environmental changes?
Explanation: Analog sensors produce an output signal that varies continuously with the measured quantity, whereas digital sensors output in discrete steps, such as on or off states. Not all analog sensors are limited to light measurement, nor are digital sensors to temperature. Both analog and digital sensors usually require power. Accuracy depends on many factors and is not inherently higher in analog or digital types.
Why is feedback from sensors important when using actuators in a closed-loop embedded control system, such as in automatic temperature regulation?
Explanation: Feedback ensures that the system constantly monitors its actual output and adjusts the actuators to maintain the desired state, which is crucial for closed-loop control like temperature regulation. It is not used to power actuators; separate power circuits serve that purpose. Removing sensors would disable the feedback mechanism, and feedback does not affect voltage supplied to actuators—its purpose is informational, not electrical.
In an agricultural monitoring system, which sensor would be most suitable for automatically measuring soil moisture to trigger irrigation?
Explanation: A soil moisture sensor specifically detects water content in the soil and helps automate irrigation by providing accurate measurements. A gas flow sensor measures the movement of gases, not soil properties. A rotary encoder detects shaft position or angular movement. A PIR sensor measures motion by detecting infrared radiation, which is unrelated to soil moisture.