Which semiconductor device has a resistance that varies with temperature and is used for temperature sensing?

Which semiconductor device has a resistance that varies with temperature and is used for temperature sensing?

• A. Thermocouple
• B. Thermistor
• C. Resistor
• D. Diode

Answer: (B)

A thermistor is a resistor made from semiconducting material whose resistance changes significantly with temperature, making it ideal for temperature sensing. In an NTC thermistor, resistance decreases as temperature rises, so you can determine temperature by measuring the resistance (often using a simple voltage divider or a constant-current setup). This strong and predictable resistance-temperature relationship is why thermistors are the go-to choice for sensing temperature. Thermocouples generate a voltage in response to a temperature difference, not a change in resistance, so they’re used for temperature measurement in a different way. A regular resistor is designed to have a fixed resistance, with only small, often negligible, changes due to temperature—not suitable for sensing across a wide range. A diode’s temperature effect shows up as changes in forward voltage, not primarily as a resistance that tracks temperature for sensing, though diodes can be used in some temperature compensation schemes.

A thermistor is a resistor made from semiconducting material whose resistance changes significantly with temperature, making it ideal for temperature sensing. In an NTC thermistor, resistance decreases as temperature rises, so you can determine temperature by measuring the resistance (often using a simple voltage divider or a constant-current setup). This strong and predictable resistance-temperature relationship is why thermistors are the go-to choice for sensing temperature.

Thermocouples generate a voltage in response to a temperature difference, not a change in resistance, so they’re used for temperature measurement in a different way. A regular resistor is designed to have a fixed resistance, with only small, often negligible, changes due to temperature—not suitable for sensing across a wide range. A diode’s temperature effect shows up as changes in forward voltage, not primarily as a resistance that tracks temperature for sensing, though diodes can be used in some temperature compensation schemes.