HEAT

                                                                      
INTRODUCTION

HEAT: Heat is a form of energy which makes a substance hotter. Actually heat energy is a part of energy internal energy which is transferred from one body to the other on account of temperature between the two bodies 

       its s.i unit is joule

CALORIE:It is another unit of heat.The amount of heat required to increase the temperature of 1 gram of water from 14.5'C to 15.5'C at a pressure of 1 atmosphere is called 'one calorie'

TEMPERATURE : Degree of hotness or coldness of the body
is called 'TEMPERATURE'
     IN other words, temperature of a body is thermal state or condition of the body which determines the direction of flow of heat, when it placed in contact with another body.Its S.I unit is kelvin.Other common unit of temperature is degree celsius ('C)

EFFECT OF HEAT:
(i)Change in temperature
(ii)Change in shape and size
(iii)Change in physical state
(iv)Change in physical and chemical properties

Thermometry: The branch of physics dealing with the measurement of temperature is called 'Thermometry'.
Thermometer: Thermometer is a device which is used to measure the temperature of body.

Fixed points: Two fixed temperature are required for a temperature scale in the measurement of temperature.These two fixed temperature are called 'Fixed points' of the temperature scale.

Lower fixed points: The temperature at which pure ice melts under standard atmospheric pressure is taken as the lower fixed points of temperature scale .e.g-The Lower fixed point on celsius scale is 0'C.

Upper fixed points: The temperature at which pure water boils under standard atmospheric pressure is taken as upper fixed fixed point of temperature scale.e.g.-The upper fixed point on celsius scale is 100'c

FUNDAMENTAL INTERVAL: The distance between the lower fixed point and upper fixed point on a temperature scale is called fundamental interval .The fundamental interval is divided into a number of equal division ------s.Each division is called One degree.

Ice-point: The temperature at which pure ice melts under standard atmospheric pressure is called 'Ice-point'.

Steam-point: The temperature at which pure water boils under standard atmospheric pressure is called 'Steam point'.

Important temperature scales:

Celcius Scale or Centigrade Scale-The lower and upper fixed points of this scale are 0'C and 100'C respectively and the fundamental interval is divided into 100 divisions. Each division is called 1 degree.

 Fahrenheit scale- The lower and upper fixed points of this scale are 32'F and 212'F respectively and the fundamental interval  is divided into 180 divisions.

Kelvin scale or absolute scale- The lower and upper fixed points of this scale are 273K and 373k and the fundamental interval is divided into 100 divisions.

Reaumer scale- The lower and the upper fixed points of this scale are 0'R and 80'R respectively and the fundamental interval is 80.

Ranking scale-The lower and the upper fixed points of this scale are 460' Ra and 672' Ra respectively and the fundamental interval is 212.

Absolute zero scale:The temperature at which average kinetic energy of molecules of a substance becomes zero is called 'Absolute Zero'.It is the lowest temperature that can be reached.The