In this post, we shall learn about What is Heat and Temperature? .We shall also learn about What is the Unit of Measurement of Heat and Temperature? While understanding the basic concepts What is Heat and Temperature in Physics? Let’s see what all are we going to cover today (See the Table of Contents)
What is Heat
Heat is the Natural Cause of Cold and Hot Feelings. Heat refers to something that when heated, an object is heated and cooling is discarded. There is no size, volume, mass, smell or colour of heat. Therefore, heat is not material.
Heat is a form of Energy: Various experiments have shown that heat is generated in exchange for some energy. According to the source of energy indestructibility, it is said that the energy expended to generate heat is converted to heat without wasting. For this reason, heat is regarded as a kind of force.
Definition of Heat: Heat is a type of energy if accepted, the object is usually heated and cooled if discarded.
What is Temperature:– Heat or temperature is the thermal state of an object. This state ensures that when one object is in contact with another object, the first object will heat the second object or The second object will receive heat.
Difference Between Heat and Temperature
|Heat is a special form of energy.
||Temperature is the thermal state of an object that controls the direction of heat flux
|The heat exchange between the two objects does not depend on their total heat.
||Temperature exchange between the two objects depends on the difference in their heat.
|Although two objects have different amounts of heat, the Temperature of the two objects can be one.
||Although two objects have the same amount of heat, there is no assumption that the Temperature of the two objects will be the same
|Calorimeter is measured by the heat received or discarded by the object.
||The temperature of the object is measured using a thermometer.
|The total heat changes during the change of conditions.
||Warmth remains the same when conditions change.
|The unit of heat in the SI method is ‘Jul’ and CGS method is ‘Calories’.
||The unit of warmth in the SI method is ‘Kelvin’and Degrees Celsius in the CGS method.
The effect of heat changes many physical properties of a substance. Examples of solid, liquid and gas volume expansion, change in circulation resistance. Along with the change in temperature, heat is measured by employing the regular variation of all these physical properties of the substance. This type of substance is called a warming criterion.The thermometer is the device by which the temperature of an object is measured precisely and accurately.
Medical Thermometer: – On a medical thermometer, the perforation is slightly curved on the coil, it acts as a knot.
Thermometric Scale:- Two specific warming constants are taken to create a warming scale. This warmth is called a constant.
Lower fixed Point:– Evidence that at warmer atmospheric pressure, pure ice becomes melted water or pure water becomes ice, which is called a low point or ice point.
Upper fixed Point:-The heat at which the pure water evaporates into the atmosphere at atmospheric pressure is called the upper constant or the boiling point.
Fundamental Interval:-The initial interval is called the warm-up interval between the thermometer’s lower-constant and upper-constant.
Thermometer scales are created by dividing this interval into several equal parts. Each part is called a degree. There are usually two types of thermometer scale, namely [a] Celsius scale and [b] Fahrenheit scale.
[a] Celsius Scale:- Celsius was formerly called Centigrade. On this scale, the lower end is divided into 0oC and the upper constant is 100oC. Each share is called one degree Celsius. An astronomer in Sweden named Anders Celsius invented this scale in 1742.
[b] Fahrenheit Scale:-The scale divides the median of the lower constant to 32oF and the upper constant to 212oF. Each share is called one degree Fahrenheit. G.D. Fahrenheit invented this scale in 1720.
Relationship of Celsius and Fahrenheit Scale
The warming interval between the low-constant and upper-constant of the Celsius and Fahrenheit scales, that is, the initial intervals, is divided into 100 and 180, respectively. So,
100 cells on Celsius scale = 180 cells on the Fahrenheit scale.
Therefore, 1 house on the Celsius scale = 9/5 cells on the Fahrenheit scale.
Let’s say, again, Lesson C on the Celsius scale and Lesson F on the Fahrenheit scale. Since the Celsius scale’s freezing point is 0oC and the Fahrenheit scale’s temperature is 32oF, In both cases the initial intervals, respectively
this is the relation between Celsius and Fahrenheit scale.
Unit of measurement of heat
Calorie: – 1 gram of pure water, the amount of heat required to increase the temperature 1oC 1 calorie to him. In the CGS method, the unit of heat is calories.
Joule: – The unit of heat energy is expressed in the SI method. The unit of measure of heat in the SI method is Joule. 1 calorie = 4.1825 Jul = 4.2 Jul (approx) .
Factors Determining the Quantities of Heat
The amount of heat in an object depends on the mass, warmth and nature of the object.
- Dependency of mass: – Different masses of the same substance receive or discard different amounts of heat to increase or decrease the same amount of heat. This is proportional to the mass of the heat received or excluded.
- Dependence on heat: – The heat received or discarded by an object of a certain mass is proportional to the increase or decrease in heat.
Dependence on the nature of the object: – The amount of heat received or discarded by an object depends not only on the difference of mass or heat of the object but also on the nature of the substance that the object is made of. This particular religion of matter is called its relative heat. For example, if the heat of the relative heat of the water is higher than that of the milk with the same mass of water and two containers of milk and sitting on the same wool (that is, providing heat at the same rate), the heat of milk is higher than the water.
As the relative heat of water is higher than that of other liquids, its heat and heat capacity are high. So water is more suitable for baking.
Definition: – any of the substances in a single mass, the amount of heat required to increase the temperature of one degree, the material of the specific heat is.
[A] Definition of Relative Heat in CGS Method: – The amount of calorie heat required to increase the heat of 1oC of a substance of one gram mass is called the relative heat of that substance. In this method, the unit of relative heat is calories per gram per degree Celsius (cal / gmoC).
‘Relative heat of copper is 0.09 cal / g degrees Celsius ‘ – This means that one gram of copper requires 0.09 calories of heat to increase 1oC.
[B] Definition of Relative Heat in SI Method: – The amount of heat required to increase the heat of a kilogram of mass or 1oC is called the relative heat of that substance. Its unit is – Jol/kg Kelvin or degrees Celsius (J / kg K or, J / kg C). Relative heat levels = [ML2T-2 / MK] = [L2T-2K-1]
The ‘ iron relative heat of 462 J / kgK ‘ implies that 46 kg of heat is needed to increase the heat of 1 kg of iron to 1K. The relative heat of water is highest. Relative heat of the water in CGS method = 1 cal / gmoC and relative heat of the water in SI method = 4200 J / kgK.
Principle of Calorimetry
When two objects of different warmth are in contact with each other, heat is exchanged between them to come into thermal equilibrium. The warm object tends to dissipate heat and the cooler object receives heat. This acceptance and exclusion of heat will continue until the heat of both is equal. If it is assumed that no heat was wasted during acceptance and exclusion, the cooling object receives the same amount of heat as the warm object will discard. That is, heat dissipated by warm objects = heat received by cooling objects. This is the principle of calorimetry. This condition applies even if two or more objects are in contact with each other.
Warning : - No heat will be wasted during heat acceptance and exclusion or no heat will enter inside.
 There will be no chemical reactions between the two materials or dissolve in each other. Because in every chemical reaction or solution some heat is absorbed or absorbed which cannot be assumed as calorimetry.
An object devoid of warmth or to increase or decrease the amount of heat received by the objects for
Suppose the mass of an object = m g, relative heat = s , then in the CGS method by the definition of relative heat—
- 1gC of taken or discarded heat to increase or decrease the heat of 1oC of the object = s calories
- m Accepted or discarded heat = ms calories to increase or decrease the heat of 1oC of gram matter
- Thus, the heat received or excluded to increase or decrease the t oC warming of m gram material = mst calories
- Therefore, the heat received or excluded is H = mst calories.
- That is, heat received or discarded = mass of the object x relative heat x increase or decrease in heat.
- SI method: If the mass of the object = m kg , the relative heat = s J / kgK and the increase or decrease of heat = TK , the heat received or discarded by the object is H = msT joule.
The Thermal Capacity of a Body
- Definition: – The amount of heat needed to increase the heating of an object to 1 Kelvin or 1oC is called the thermodynamic or thermodynamics of that object.
[A] In CGS method: – The heat of the object is C = ms cal / oC, where the mass of the object = m g and the relative heat = s cal / gmoC.
[B] In the SI method: – The heat of the object is C = ms Jol / Kelvin (J / K), where the mass of the object is = m kg and the relative heat = s J / kgK. Heat Level = [ML2T-2K-1]