ch = 4 ( heat and its effect )

ch = 4 ( heat and its effect )

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chapter 4 (heat)

• heat a form of energy

• how to measure heat

• thermometer

• transfer of heat

• conduction , convention and radiation

• conductors and insulators

heat a form of energy..

*doing work produces energy.this energy is called heat energy. when we rub our hands we feel warm and heat energy is produced due to rubbing. the heat get transfered due to the difference in temperature.

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how to measure heat

*Temperature is measure of degree of hottness or coldness of a body. The SI unit of temperature is kelvin(k). it is a measure of heat energy present in it. THERMOMETER is a device to measure the hotness of a body.

thermometer

*it is a tool by which we can measure temperature. the most common type of thermometer used in the laboratory for temperarture measurement is the mercury thermometer. there are two scales on the stem of a thermometer-a Celsius scale and faharenheit scale.

transfer of heat

*heat flows from hotter objects to colder objects.for examples when we cook some food in a frying pan,it become hot when kept on a flame.this is because the heat passes from the frame to the utensil.

conduction

*process of transfer of heat from the hotter end to the colder end of an object.

convection

* process of heat transfer in which heat is carried from the hotter part of a substance to its colder part by the movement of hot particles in it.

convection

* process of heat transfer in which heat is carried from the hotter part of a substance to its colder part by the movement of hot particles in it.

radiation

*The process in which heat flows from one object to either through a medium or through vaccum,without heating up the space in between, is called a radiation.

conductorsand insulators

* the material which allow heat to pass through them are called conductors of heat,such as iron,copper etc. the material which do not allow heat to pass through them are called insulators. for ex = rubber,cloth,wood etc..

revision time

lets revise topic

• heat is a form of energy

• thermometer is a device to measure temperature

• mercury is used as a thermometric fluid

• clinical thermometer is is used to measure human body temperature

• heat always flow from a hotter body to a colder body

• heat can transfer by three mode conduction,conventionand radiation.

Multiple Select

the unit of measurment of temperature is _____.

• meter

• degree celcius

• kilograms

Multiple Select

the normal temperature of a human body is _________.

• 37 degree (C)

• 98 degree (F)

• 98 degree(c)

Multiple Choice

heat energyfrom the sun reaches by us by the process of _________.

• conduction

• convention

• radiation

Multiple Choice

A thermometer fluid ?

• mercury

• clinical

Multiple Choice

measure of heat?

• thermometer

• temprature

Multiple Select

another name of bad conductors of heat

• conductors

• insulators

Multiple Select

mode of heat transfer from the sun to earth

• convention

• radiation

• none of the above

Multiple Select

which of these device are used to measuring tempurature ?

• temprature

• ammeter

• none of the above

Multiple Choice

The balloon increases in size because

• The air inside the balloon expands on heating

• The air increases its weight on heating

Multiple Choice

Conduction of heat takes place only in .................

• Solids

• Liquids

• Gases

• Air

Multiple Choice

In Celsius scale, the lower fixed point is ....................

• 100

• 32

• 212

• 0

Multiple Choice

The sensation of hotness or coldness is caused by ..................... ENERGY

• magnetic

• electrical

• heat

• mechanical

thank you for watching and reading this lesson

by urvi