Heat

Question 1

Effects of heat

Answer 1

Expansion
Change in state
Change in temperature
Chemical changes

Question 2

We wear woolen clothes in winter to keep ourself warm

Answer 2

Air, Which is the bad conductor does not allow our body heat to escape

Question 3

Mercurys used in thermometer

Answer 3

Is a good conductor of heat

Question 4

The process of transfer of heat in solids from origin of higher temperature to region lower temperature without the actual moment of molecules called

Answer 4

Conduction

Question 5

The flow of heat through a fluid from places of higher temperature to place of lower temperature by a movement of fluid itself

Answer 5

Convection

Question 6

Examples of convention in daily life

Answer 6

1 Hot air balloon
2 breeze (land breeze and sea breeze)
3 wind
4 chimney

Question 7

Radiation is the flow of heat from one place to another by means of _______

Answer 7

Electromagnetic waves

Question 8

Radiation is limited by all bodies above

Answer 8

0K

Question 9

We can observe all the 3 ways of heat transfer

Answer 9

Wiring wood

Question 10

White or light coloured crackers are good reflector of heat

Answer 10

They keep us cool during summer

Question 11

Base of cooking utensils is blackened

Answer 11

Because black surface observe more heat from the surroundings

Question 12

Surface of airplanes highly polished

Answer 12

Because it help to reflect most of the heat radiation from the Sun

Question 13

_____ is there degree of hotness or coldness of the body

Answer 13

Temperature

Question 14

Kelvin scale is also known as

Answer 14

Absolute scale

Question 15

Fahrenheit scale

Answer 15

32-212°F

Question 16

Celsius scale

Answer 16

0-100°C

Question 17

Formula for convertian Celsius scale to fahrenheit scale

Answer 17

F=9/5C+32
C=5/9(F-32)

Question 18

Temperature at which is the molecules of a substance have thier lowest possible energy

Answer 18

0K

Question 19

SI unit of temperature

Answer 19

Kelvin

Question 20

The solid liquid gases faces of water can co exist in equilibrium at

Answer 20

273.16K

Question 21

Kelvin is defined as

Answer 21

1/273.16 of the triple point of temperature

Question 22

If Fahrenheit scale is 0°F then Kelvin and Celsius scale will be

Answer 22

-18°C and 255K
Vice versa

Question 23

If Fahrenheit scale is 32°F then Kelvin and Celsius scale will be

Answer 23

0°C and 273.15K

Question 24

If Fahrenheit scale is 212°F then Kelvin and Celsius scale will be

Answer 24

100°C and 373.15 K

Question 25

If Fahrenheit scale is -460°F then Kelvin and Celsius scale will be

Answer 25

-273°C and 0 K

Question 26

The temperature at which the pressure and volume of a gas theoretically reaches 0 is called

Answer 26

Absolute zero For all gases the pressure extrapolates to zero at the temperature -273.15°C. it is known as absolute zero or 0 K

Question 27

Temperature of boiling point of water

Answer 27

373.15 K 100°C 212°F

Question 28

Temperature of melting point of ice

Answer 28

273.15 K 0°C 32°F

Question 29

Absolute zero

Answer 29

0 K -273 °C -460 ° F

Question 30

Convert celcius to kelvin

Answer 30

K= C + 273.15

Question 31

The amount of heat energy observed or lost by a body is determined by 3 factor

Answer 31

1 Mass of the body 2 change in temperature of the body 3 natural the material of the body

Question 32

Formulas specific heat capacity

Answer 32

C. = Q ------------ m ∆T T change in temperature M mass of the body Q quantity of heat obsorbed

Question 33

The SI unit of specific heat capacity

Answer 33

J kg^-1 K^-1

Question 34

The amount of heat required to the raise the temperature of 1 kg of the substance by 1 degree Celsius or 1K

Answer 34

Specific heat capacity

Question 35

________ has the highest specific heat capacity and its values ______

Answer 35

Water 4200 J/kg K

Question 36

Water absorbs large amount of heat for unit raise in temperature

Answer 36

Water is used as a coolant in car radiators and factories to keep engine and other machinery parts cool

Question 37

Water in its various form as different specific heat capacity

Answer 37

Water 4200 J/ (kg K) ice. 2100 J /(kg K) stream. 460 J/(kg K)

Question 38

Heat capacity or thermal capacity

Answer 38

Is defined as the amount of heat energy required to raise the temperature of body by 1 degree Celsius C' =Q/T

Question 39

S.I unit of heat capacity

Answer 39

J/K

Question 40

The case of water melting and boiling occurred at

Answer 40

0°C

Question 41

The process in which year solid is converted to liquid by obsorbing heat is called

Answer 41

Melting or fusion

Question 42

Boiling point as well as condensation point of water is

Answer 42

100°C

Question 43

The process in which a solid is converted to gas state is called

Answer 43

Sublimation

Question 44

The amount of heat energy observed or released by a substance during a change in its physical States without any change in its temperature

Answer 44

Latent heat

Question 45

Latent heat of fusion

Answer 45

heat energy is absorbed by the solid during melting and an amount of heat energy is liberated by the liquid from during freezing without any temperature change

Question 46

Latent heat of vaporization

Answer 46

Heat energy is observed by a liquid during vaporization and equal amount of heat energy is liberated by the vapour during condensation without any temperature change

Question 47

Specific latent heat

Answer 47

Amount of heat energy observed or liberated by unit mass of a substance during change of state without causing any change in temperature L=Q /m

Question 48

SI unit of specific latent heat is

Answer 48

J/kg

Question 49

Convection take place in _______ and conduction take place in _______

Answer 49

Liquid and gas Solid

Question 50

Calories the unit of

Answer 50

Heat

Question 51

Two cylindrical rod of same length how the area of cross section in the ratio 2:1 if both the material made up of same material which of them conduct heat faster a) both rod b) rod 2 c) rod 1. d) none

Answer 51

Rod 1

Question 52

Your device in which season loss of heat due to conduction convection and radiation is minimised is

Answer 52

Thermos flask

Question 53

The fastest mode of heat transfer is

Answer 53

Radiation

Question 54

Liquid and gases are generally _____ conductor of heat

Answer 54

Poor

Question 55

The fixed temperature at which matter changes state from solid to liquid is called

Answer 55

Melting point