Commonly used Thermistors for temperature measurement have

Explanation:

Thermistors for Temperature Measurement

Definition: A thermistor is a type of temperature-sensitive resistor that exhibits a significant change in resistance with a change in temperature. It is widely used for temperature measurement, control, and compensation in various applications due to its high sensitivity and precision.

Correct Option Analysis:

The correct answer is:

Option 2: Negative temperature coefficient

This option correctly describes the behavior of commonly used thermistors for temperature measurement. Negative Temperature Coefficient (NTC) thermistors are characterized by a decrease in resistance as the temperature increases. This property makes them ideal for precise temperature measurement applications.

Working Principle:

NTC thermistors operate based on the principle that their resistive material exhibits a negative temperature coefficient. As the temperature rises, the thermistor's resistance decreases exponentially. This behavior occurs due to the increase in the number of charge carriers (electrons and holes) available in the material, which enhances conductivity. The relationship between resistance (R) and temperature (T) is often expressed mathematically as:

R(T) = R₀ × e^(β/T)

Where:

• R₀: Resistance at a reference temperature
• β: Material constant
• T: Temperature in Kelvin

Advantages of NTC Thermistors:

• High sensitivity to temperature changes, making them suitable for precise measurements.
• Compact size and ease of integration into electronic circuits.
• Cost-effective solution for temperature sensing and monitoring.
• Wide range of operating temperatures, enabling diverse applications.

Applications:

• Temperature measurement in electronic devices, such as thermostats and temperature sensors.
• Overcurrent protection in circuits by monitoring temperature rise.
• Compensation for temperature-induced variations in electronic components.
• Used in automotive, medical, and industrial equipment for temperature control.