Changes of resistance with temperature, Physics

Changes Of resistance with temparature:

The resistance of all materials changes with changes in temperature.  The resistance of all pure metal increases with temperature.  The resistance of electrolytes, insulators, carbon and semi-conductors decreases with increasing temperatures.

If it is assumed that the resistance change is in proportion to the temperature change, then the ratio provides an indication of the material behaviour.  It is necessary however, to relate the change of resistance to its initial value.  A large value resistor will change its value more than a small value resistor for the same temperature change.

Suppose the resistance of a material at 0ºC (to) is R

and at some other temperature (t) the resistance is Rt

the change of resistance is Rt - Ro.

But the change of resistance is per unit value of the original resistance is given by;

          R  = 893_changes in resistance.png

this resistance change has been brought about by a temperature change t equal to t -to (to being 0º).

Hence the change in resistance, caused by a 1ºC change in temperature is;

            R/T = 1288_changes in resistance1.png   =  1214_changes in resistance2.png  because t = 1 and to = 0

This ratio is called the temperature co-efficient of resistance.

 

 

 

 

 

Posted Date: 9/13/2012 3:01:31 AM | Location : United States







Related Discussions:- Changes of resistance with temperature, Assignment Help, Ask Question on Changes of resistance with temperature, Get Answer, Expert's Help, Changes of resistance with temperature Discussions

Write discussion on Changes of resistance with temperature
Your posts are moderated
Related Questions
A rigid object is a body with a exact and unchanged size and shape i.e. a body is said to be rigid if the distance among any two particles of the body remains invariant.

Verify the principle of potentiometer. Illustrate a circuit diagram used to compare the e.m.f. of two primary cells. Write the formula used. How can the sensitivity of a potentiome

What is Gravity Force (Fgrav): Force with which the earth, moon, or massively large object attracts another object towards itself. By meaning, this is the weight of the object.

A point charge q is imbedded at the center of a sphere of linear dielectric material (with susceptibility and radiusR). Find the electric field, the polarization, and the bound cha

Energy Transformation for a Pendulum Because there are no external forces doing work and the total mechanical energy of the pendulum bob is conserved. The conservation of mecha

how may six digit numbers can be made in which the sum of the digits is even?

Q. What is dual character of light? Light behaves as particles of energy in the higher energy region as well as as waves in the lower energy region.

Materials, which provide a path to the magnetic flux, are classified as (A) Insulating materials. (C) Magnetic materials. (B) Semi conducting materials. (D) Die

Plot the Bremsstrahlung emitted (intensity vs energy) from a copper target for (i) both 15 keV and 30 keV electrons, (ii) for 15 keV electrons at both 10 and 50 mA current and (iii

An airplane accelerates down a runway at 3.20 m/s2 for 32.8 s until is finally lifts off the ground. Determine the distance traveled before takeoff. I need help of an expert who ca