Thermistors, Physics


Insulators and semi-conductors behave in a different way when the temperature increases, because their resistivity decreases. That is: the resistance of an insulator and of a semi-conductor decreases with temperature increase, (their resistance-temperature coefficient is negative!). This feature can be used to advantage as the following example shows.

One example of this effect occurs in a thermistor, which is a thermally sensitive resistor whose resistance alters with temperature; a negative temperature coefficient (n.t.c.) thermistor is one whose resistance reduces with increase in temperature. A thermistor is used in the cooling-water temperature-measuring circuit of a car or lorry; it is inserted in the cooling water and connected in series with the battery and temperature gauge. As the water temperature rises, the resistance of the n.t.c. thermistor falls and allows more current to flow through the temperature gauge; this causes the gauge to indicate variations in water temperature.

Posted Date: 9/13/2012 3:09:36 AM | Location : United States

Related Discussions:- Thermistors, Assignment Help, Ask Question on Thermistors, Get Answer, Expert's Help, Thermistors Discussions

Write discussion on Thermistors
Your posts are moderated
Related Questions
Q. What do you mean by additive nature of charges? Give an example. Additive nature of charge The entire electric charge of a system is equal to the algebraic sum of electric

Balmer series (J. Balmer; 1885) An equation that describes the emission spectrum of hydrogen while an electron is jumping to the second orbital; four of the lines are into the

The liquid calculates milliliter, mL, is the same as 1 cm 3 . How many milliliters of liquid can be held in a 2.5-m 3 container?

What angle we take between magnetic field and plane of loop....discuss the cases when induced emf is zero in a rotating frame. Ans) We know that Magnetic Flux through a given area

The Law of Reflection While a ray of light strikes a plane mirror and the light ray reflects off the mirror. Reflection includes a change within direction of the light ray. The

A helium atom is in a galaxy travelling at a speed of 4.89 x 10 6 m/s away from the Earth. An astronomer on Earth observes a frequency from the helium atom of 6.52 x 10 14 H

The helicopter view in fig. p3.29

N-Type Substances: When a small quantity of Arsenic or Phosphorous (group VA elements) is added to silicon or Germanium, it becomes good conductor of negative charges, such a s

Chemical action in lead acid battery: When the lead acid battery is delivering current, the sulphuric acid breaks up into Hydrogen ions (H 2 ) carrying a positive charge and Su

Unpolarized light: In ordinary light (light from sun, bulb etc.) the electric field vectors are given in all directions in a light is known as unpolarized light. The oscillation o