# Physics IX Notes Chapter 8 Thermal Properties of Matter

## Physics IX Notes Chapter 8 Thermal Properties of Matter

Q.1 Define heat and temperature? Also, show deference b/w them?

Ans. 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 are called heat.

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

ð  Difference b/Wheat and temperature

 S.NO Heat S.NO Temperature. 1 it is the total K.E of molecules of a body. 1 It is the average K.E of molecules of a body. 2 It gives the sensation of warmth 2 It is the degree of coldness or the hotness of a body. 3 Its units are joules and calories. 3 Its units are kelvin, centigrade, and Fahrenheit.

Q.2 Define thermometry? Also, explain thermometric property? And the temperature scale?

Ans. Thermometric: – The branch of physics which deals with the measurement of temperature.

Thermometric property:-we measure temperature by on an instrument called thermometer. For the construction of a thermometer, we use certain the physical property of matter which decreases or increases uniformly with the change in temperature, 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 thermometer.

Temperature Scale:- see Q4

Q.3 What is the thermometer? Also, explain liquid in glass thermometer and clinical thermometer?

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

ð  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 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 labor tries and it has a temperature of – 10oc to 110o c.

ð  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 glass stem near the bulb so that to prevent the easy flow of mercury toward the bulb.

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

Q.4 what is meant by the thermometric scale? Also, discuss different sales?

Ans. 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.