Blog Tag Heat

Difference between Evaporation and Vaporisation

Both the processes convert liquid into gaseous state but there are four major differences between the two processes. Evaporation takes place at all temperature but vapourisation takes place only at a fixed temperature which is the boiling point of the liquid. Evaporation is a slow and gradual process whereas vapourisation is a rapid and violent . . .

Number of division between Ice point and Steam point of Fahrenheit, Celsius and kelvin scale

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Heat

Heat is a form of energy which produces the sensation of hotness and coldness. Its unit is joule (J) and calorie (cal). Heat flows from a hot body to cold body when they are kept in contact.  When heat is absorbed by a body, its temperature rises while if it loses heat energy, its temperature falls. . . .

Units of heat

Since heat is a form of energy, therefore the S.I. unit of heat is joule (symbol J). The other common units of heat are calorie (symbol cal) and kilocalorie (symbol kcal), where                            1 kcal=1000 cal One calorie is defined as the heat energy required raising . . .

Thermometer

 A thermometer is a device that measures temperature .A thermometer has two important elements: (1) A temperature sensor (e.g. the bulb of a mercury in-glass thermometer) in which some physical change occurs with temperature. (2) Some means of converting this physical change into a numerical value (e.g. the visible scale that i . . .

Temperature

A temperature is an objective comparative measurement of hot or cold. It is measured by a thermometer. Several scales and units exist for measuring temperature, the most common being Celsius (denoted °C; formerly called centigrade), Fahrenheit (denoted °F), and Kelvin (denoted K).      . . .

Thermal expansion

Thermal expansion is the tendency of matter to change in shape, area, and volume in response to a change in temperature. Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, the kinetic energy of its molecules increases. When a substance (solid, liquid or gas) is heated , . . .

Thermal Expansion in Solid

A solid has a definite shape. When a solid is heated, it expands in all the directions, hence the length, area and volume all increase on a heating a solid.The increase in length of a solid is called the linear expansion. The increase in area is called the superficial expansion and the increase in volume is called the cubical expansion . . .

Applications of Thermal Expansion in daily life

The telephone and the electric wires when are connected in summer between the two poles, they are kept loose so that they may not break when they contact in winter. on the other hand , if the wires are connected in winter between the two poles, they are kept tight because they will expand in summer and will sag. The wooden wheels of a bullock-cart . . .

Effects of heat

The heat produce mainly the following three effects: The change in temperature of the body. The change in size or shape of the body. The change in state of the body. . . .

Thermal Expansion in Liquid

Like solid, liquid also usually expands liquid on heating. Liquids expand much more than the solid when heated. Liquids do not have a definite shape, but they have a definite volume, therefore liquids have only the cubical expansion.     . . .

Thermal Expansion in Gases

Gases also expand when they are heated. Gases expand much more than the liquids and the solids. Like liquids, the gases do not have a definite shape, so they also have only the cubical expansion. . . .

Difference between Laboratory thermometer and Clinical thermometer

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Change in different states of matter

Matter cannot be created or destroyed, but can change from one state to the other with the application or removal of heat (temperature). Each time matter changes state, it is simply the movement of molecules in them speeding up or slowing down. For example:Let us use water as an example. At room temperature, water is . . .

Behaviour of Matter

The particles in solids, liquids and gases all behave in different ways but result in a similar way. They all expand when heated up. Solids:  The particles in solids vibrate more and knock against each other when heated and result in taking up more space. The property of solids (metal) expansion makes it possible to join two metal pieces withou . . .

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