Physics IX Notes Chapter 8 Thermal Properties of Matter

Heat:- The form of energy which transfers from one body to another body due to difference of temperature between them is called heat
(OR) The total K.E of molecules of a body is called heat.

Temperature:-The degree of coldness or hotness a body concerning some standard is called temperature (OR) The average K.E of molecules of a body is called temperature.

Thermometric: – The branch of physics which deals with the measurement of temperature.
Thermometric property:-we measure temperature by an instrument called thermometer. For the construction of a thermometer, we use certain properties of matter which decrease or increase uniformly with the temperature change, and this property is used for measurement of temperature which is known as thermometric property.

Usually, we use the property of expansion. For example, the expansion of mercury and alcohol is a uniform that is mostly used for measurement of temperature in thermometers.
Temperature Scale:- see Q4

Thermometer:- The instrument which is used for measurement of temperature is called a thermometer; it is based on the principle of expansion of liquids on heating.

the liquid in glass thermometer:- it consists of a graduated glass tube whose one end is sealed and the other is filled with a bulb. And glass is filled with mercury. When the bulb of the thermometer is heated the mercury expands up and we can easily record the reading liquid in a glass thermometer is most commonly used in labour tries and it has a temperature of – 10oc to 110o c.

clinical thermometer:- this thermometer consists of a glass stem whose one end is fitted with a bulb and others are sealed. The stem is filled with some standard liquids like mercury etc.
A small bend is given to the glass stem near the bulb so that it prevents the easy flow of mercury toward the bulb.

This thermometer is mostly used by doctors and nurses; its scale only extends over a few degrees on either side of normal body temperature 37oc or 98oF. Therefore the range of a clinical thermometer is from 35oc to 43oc or from 95oc to 110of.

Thermometric or temperature scale:- the scale which is made for the measurement of temperature is called temperature or thermometric scales.

There are two reference points which are called fixed points and the distance b/w these points are divided into small parts and each has given a specific numerical value. There are three scales of temperature which are given below.