Heat and temperature
Heat is a format of energy. In the nature there are different
forms of energy’s like sound, light and heat. All forms of energy’s satisfy a
concept called law of conservation of energy. According to this law energy is
neither created nor destroyed and it just converts from one form to another
form. Heat is a disordered format of energy. It is because of internal random
collisions of molecules. Measuring the hotness or coldness of a body directly
without the concept of temperature is very difficult. The human perception
never gives the correct understanding of hotness or coldness of a body as it is
just comparative. We always compare the hotness or coldness of the body with
respect to the another body and it will never give you correct results.
To measure heat, we have a physical quantity called a
temperature. Temperature is a measure of heat energy. Heat is the cause and the
temperature is its effect. Heat always flows from a body of higher temperature
to your body of lower temperature. Temperature is treated as a fundamental
physical quantity and it does not depend on any other physical quantities.
To measure temperature we have different kinds of scales like
centigrade scale, Foreign heat scale and Kelvin scale. There is a simple
relation among all this scales. Though the scales are different, they are
measuring the temperature of the same body and it shall be the same. Just
because the scale is different the number appears like different one but the
original temperature of the body is same. The following is the relation between
different kinds of scales.
It could be easily noticed that difference in the temperature
is in degrees centigrade is similar to that of the degree Kelvin.
We can solve a small problem where we are going to identify
at what temperature the Kelvin scale and the foreign heat scale are going to
show the same reading ?
To measure the temperature we have different kinds of
thermometers. Each of this thermometers works basing on a certain principle.
For example ,mercury Thermometer works on the principle that when the
temperature is increase, the volume expansion of the mercury is a uniform and
proportional. Similarly the volume of a gas like hydrogen increases proportionately
with temperature at constant pressure and this concept is used in designing gas
Thermometer.
For a ohmic material,with respect to the increase of the
temperature resistance increases in the proportionally and this concept also
can be used to designing a Thermometer called resistance Thermometer.
We can derive a small formula to find the temperature of a
body using any of these Thermometers as shown below.
Related Posts
No comments:
Post a Comment