The correct answer is: B. Negative temperature coefficient
A thermistor is a type of resistor whose resistance decreases with increasing temperature. This is in contrast to most other resistors, which have a positive temperature coefficient and whose resistance increases with increasing temperature.
Thermistors are made from semiconductor materials, such as oxides of metals such as manganese, nickel, cobalt, copper, and iron. When these materials are heated, they release electrons, which increases the conductivity of the material and decreases its resistance.
Thermistors are used in a variety of applications, including temperature sensing, temperature control, and self-heating. They are also used in some types of sensors, such as smoke detectors and infrared detectors.
Here is a brief explanation of each option:
- A. Positive temperature coefficient
A resistor with a positive temperature coefficient is one whose resistance increases with increasing temperature. This is the most common type of resistor.
- B. Negative temperature coefficient
A resistor with a negative temperature coefficient is one whose resistance decreases with increasing temperature. This is the type of resistor that a thermistor is.
- C. Zero temperature coefficient
A resistor with a zero temperature coefficient is one whose resistance does not change with temperature. This type of resistor is very rare.
- D. Variable temperature coefficient
A resistor with a variable temperature coefficient is one whose resistance changes with temperature, but not in a linear way. This type of resistor is also very rare.