SENSORS (IGCSE)

A sensor is:

• Something that detects a change

• Something creates a change

• Something that humans have

• Something that monitors an input

In an automated system, what type of device is a sensor?

• Input device

• Output device

• Memory device

• Processing device

Which is the best description of how a temperature sensor works

• It produces an output voltage which is proportional to the level of heat it experiences.

• If the temperature is above a certain level, it outputs a high voltage, otherwise it outputs a low voltage

• If it senses a person present it outputs a signal

• It generates heat proportional to the voltage that is supplied to it.

What does analogue mean in relation to sensors?

• The output varies smoothly and continuously over time

• The output takes on different binary values depending on the quantity being measured

• The output is recorded in a log

• The output is analysed.

Which two sensors would be used in a greenhouse control system

• pH sensor

• pressure sensor

• temperature sensor

• magnetic field sensor

Which two sensors would be used in a traffic light system

• pH sensor

• pressure sensor

• temperature sensor

• magnetic field sensor

Which two sensors would be used in a river pollution monitoring system

• pH sensor

• pressure sensor

• gas sensor

• motion sensor

Which two sensors would be used in an outdoor intruder safety light system

• temperature sensor

• light sensor

• pressure sensor

• motion sensor

Which of these is the web dictionary definition of ambient?

• relating to the immediate surroundings of something

• relating to the immediate level of something

• relating to the distant surroundings of something

• relating to the distant level of something

What is the name for a device that is used to measure the level of a physical property and provide an electrical output?

• Sensor

• Actuator

• Thermometer

• Converter