TEMPERATURE
Temperature is the degree of hotness or coldness of a body.
Temperature is measured by means of a thermometer.
For it to be used as a temperature measuring instrument
1.It must possess certain physical properties that will be able change continuosly with temperature.
2.Its physical nature must not change as a result of an increase in temperature.
Thermometers and their thermometric substances.
1.Gas thermometers : pressure of gas at constant volume.
2.Thermo-electric thermometers : current flowing in an electric circuit when one junction of two different metals (e.g.copper and constantan) is heated.
3.Resistance thermometers : increase in the resistance of a metal wire when the wire is heated.
4.Bimetallic thermometers : expansion of two metals that make up a bimetallic strip.
5.Liquid-in-glass thermometers : expansion of liquid due to increase in temperature.
The Fixed Point Of Thermometers
we have two reference of temperature,the upper fixed point and lower fixed point.
1.The upper fixed point is the temperature of steam from pure water boiling at normal atmospheric pressure.
2.The lower fixed point is the temperature of a mixture of pure ice and water at normal pressure.
Scales Of Temperature
