Matric Part 1/9th Class Physics Chapter 8 Long Question With Answer for Unit 8 Thermal Properties of Matter

Question # 1

Q no: 6(A) Explain land and Sea breeze are example of convection.?

Ans 1: Land and Sea Breezes:
Land and Sea breezes are the result of convection.
Sea Breeze:
On a hot day the temperature of the land increase more quickly than the sea. itis because the specific heat of land is much smaller as compared to water. The air above land gets hot and rise up.
Land Breeze.
At night the land codsfasterthan the sea, therforeair above the sea is warmer, rise up and the cold air form the land begins to move towards the sea.

Question # 2

Explain the consequences and application of thermal expansion.

Ans 1: Consequences of thermal expansions: the expansion of solids may damage the bridge, railway tracks and roads as they are constantly subjected to temperature changes. So provision is made during construction for expansion and contraction with temperature. For example, railway tracks bucked on a hot summer day due to expansion if gaps are not left between sections.
Bridge made of steel girders also expands during the day and contract during night. They will bend if their ends are fixed. to allow thermal expansions, one end is fixed while the other end of the girder rests on rollers in the gap left for expansion. Overhead transmission lines are also given a certain amount of sag so that they can contract in winter without snapping.
Ans 2: Application of thermal expansion: thermal expansion is used in our daily life. In thermometers, thermal expansion is used in temperature measurements. To open the cap of a bottle that is tight enough, immerse it in hot water for a minute or so. Metal cap expands and becomes loose. It would now be easy to turn it to open.
To join steel plates tightly together, red hot rivets are forced through holes in the plates. The end of hot rivet is then hammered. On cooling, the rivets contract and bring the plates tightly gripped. Iron rims are fixed on wooden wheels of carts. Iron rims are heated. Thermal expansion allows them to slip over wooden wheel. Water is poured on it to cool. The rim contracts and become tight over the wheel.

Question # 3

Q no 5(A) What is greenhouse effect.Explain the impact of greenhouse it in to Celsius scale and Kelvin scale.

Ans 1: Light from the sun contains thermal radiations of long wavelength as well as light and ultraviolet radiations of short wavelengthsglass and transparent polythenesheets allow radiations of short wavelength to pass through easily but not long wavelength of thermal radiations a green-housebecomes a heat trap. Radiations from the sun pass easily through glass and warms up the objects in a greenhouse. These objects in a greenhouse. These objects and plants such as give out radiations of much longer wavelength. Glass and transport poluthenesheets do not allow them to escapenot easily and are reflected back in the green houseGreen house effect promises betttergrowth of some plants.

Question # 4

Explain the scales of temperature

Ans 1: Temperature scales: a scale is marked on thermometer. The temperature of the body in contact with the thermometer can be read on that scale.
Three scales of temperature are in common use. These are:
Ans 2: Celsius scale or centigrade scale: on Celsius scale, the interval between lower and upper fiexd points is divided into 100 equal parts. The lower fixed point is marked as 0C and upper fixed point is marked as 100C.
Ans 3: Fahrenheit scale: on Fahrenheit scale, the interval between lower and upper fixed points is divided into 180 equal parts. Its lower fixed point marked as 32F and upper fixed poin is marked as 212F
Ans 4: Kelvin scale: In SI unit of temperature is kelvin(K) and its scale is called kelvin scale of temperature. The interval between upper and lower fixed points is divided into 100 equal parts. thus, a change in 1C is equal to a change of 1 K. The lower fixed point on this scale corresponds to 273K and the upper fixed point is referred as 373K. The zero on this scale is called the absolute zero and is equal to -273C
Ans 5: From Celsius to kelvin scale; the temperature T on kelvin scale can be obtained by adding 273 in the temperature C on Celsius scale. Thus,
T(K)= 273+C
From kelvin to Celsius scale: the temperature on Celsius scale can be found by subtraction 273 from the temperature in kelvin scale. Thus,
C=T(K)-273
From Celsius to Fahrenheit scale: since 100 divisions on Celsius scale are equal to 180 divisions on Fahrenheit scale. Therefore, each division on Celsius scale is equal to 1.8 divisions on Fahrenheit scale. Moreover, 0C corresponds to 32 F
F= 1.8C+32

Question # 5

Explain the change of state of matter

Ans 1: Change of state of matter: Matter can be changed from one state to another. For such a change to occur, thermal energy is added to or removed from a substance
Ans 2: Experiment: take a beaker and place it over a stand. put small piece of ice in the beaker and suspended a thermometer in the beaker to measure the temperature of ice.
Now place a burner under the beaker. The ice will start melting . The temperature of the mixture containing ice and water will not increase above 0C until all the ice melts and we get water at 0C. If this water 0c is further heated, its temperature will begin to increase above 0C.

Question # 6

Explain the consequences and also application of thermal expansion.

Ans 1: Consequences of thermal expansions: the expansion of solids may damage the bridge, railway tracks and roads as they are constantly subjected to temperature changes. So provision is made during construction for expansion and contraction with temperature. For example, railway tracks bucked on a hot summer day due to expansion if gaps are not left between sections.
Bridge made of steel girders also expands during the day and contract during night. They will bend if their ends are fixed. to allow thermal expansions, one end is fixed while the other end of the girder rests on rollers in the gap left for expansion. Overhead transmission lines are also given a certain amount of sag so that they can contract in winter without snapping.
Ans 2: Application of thermal expansion: thermal expansion is used in our daily life. In thermometers, thermal expansion is used in temperature measurements. To open the cap of a bottle that is tight enough, immerse it in hot water for a minute or so. Metal cap expands and becomes loose. It would now be easy to turn it to open.
To join steel plates tightly together, red hot rivets are forced through holes in the plates. The end of hot rivet is then hammered. On cooling, the rivets contract and bring the plates tightly gripped. Iron rims are fixed on wooden wheels of carts. Iron rims are heated. Thermal expansion allows them to slip over wooden wheel. Water is poured on it to cool. The rim contracts and become tight over the wheel.

Question # 7

Q no: 7(A) What causes a glider to remain air.?

Ans 1: A glider such looks like a small airoplanewithout engine. Glider pilots use of heat .These rising currents of hot air are called theimals, Gliders ride over these thermals, the upward movement of air currents in thermal helps them to stay in air for a long period.
The birds stretch out their wings and circle in these thermals, the upwordmovement of air help, birds toclimb up with it. Eagle hawks and vulture are expert thermal climber

Question # 8

Define latent heat of vaporization. explain it

Ans 1: Latent heat of vaporization: the quantity of heat that changes unit mass of a liquid completely into gas at its boiling point without any change in its temperature is caked latent heat of vaporization.
It is denoted by H_v.
When water is heated, it boils at 10C under standard pressure. its temperature remains 100C until it is changed completely into steam. Its latent heat of vaporization is 2.26*10⁶JKg^-1That is 1kg of water requires 2.26*10⁶J heat to change it completely into gases at its boiling point.
Ans 2: Experiment: take a beaker and place it over a stand. put small pieces of ice in the beaker and suspended a thermometer in the beaker to measure the temperature. Place a burner under the beaker. The ice will start melting. The temperature of the mixture containing ice and water will not increase above 0C until all the ice melts. Note the time which the ice take to melt completely into water at )C. Continue heating the water at 0C in the beaker. Its temperature will begin to increase. Note the time which the water in the beaker takes to reach its boiling point at 100C from 0C.
Continue heating water till all the water changes into steam. Note the time which the water in the beaker takes to change completely into steam at its boiling point 100C.

Question # 9

Define and explain heat capacity

Ans 1: Heat capacity: heat capacity of a body is the quantity of thermal energy absorbed by it for one kelvin(1K) increase in its temperature.
Ans 2: Explanation; heat capacity of a body is equal to the product of its mass of the body and its specific heat capacity. For example, heat capacity of 5kg of water is (5kg*4200JKg^-1) 21000JK^-1. That is 5kg of water needs 21000J of heat for every 1K rise in its temperature. thus, larger is the quantity of substances, larger will be its heat capacity.
The presence of large water reservoirs such as lakes and seas keep the climates of nearby land moderate due to the large heat capacity of these reservoirs.

Question # 10

Write a note on linear thermal expansion in solids

Ans 1: Thermal expansion; when heat is provided to any substances, the expansion of substances is known as thermal expansion.
Most of the substances solids, liquids and gases expand on heating and contract on cooling. Their thermal expansions and contractions are usually small and are not noticeable.
The kinetic energy of the molecule of an object depends on its temperature. The molecules of a solid vibrate with larger amplitude at high temperature than at low temperature.
Thus, on heating, the amplitude of vibration increase.
Thermal expansion results an increase in length, breadth and thickness of a substance.
Ans 2: Linear thermal expansion of solids: the expansion of solid along in one direction is called linear thermal expansion of solid. It has been observed that solids expand on heating and their expansions is nearly uniform over a wide range of temperature .
Unit; the unit of coefficient of thermal expansion is K^-1

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Matric Part 1/9th Class Physics Chapter 8 Long Question With Answer for Unit 8 Thermal Properties of Matter

9th Class English Medium Subjects

9th Class Urdu Medium Subjects

Online Long Questions For Chapter 8 "9th Class Physics Chapter 8 Long Question Preparation "

Physics (New Book) - 9th Class Physics Chapter 8 Long Question Preparation

Q no: 6(A) Explain land and Sea breeze are example of convection.?

Explain the consequences and application of thermal expansion.

Q no 5(A) What is greenhouse effect.Explain the impact of greenhouse it in to Celsius scale and Kelvin scale.

Explain the scales of temperature

Explain the change of state of matter

Explain the consequences and also application of thermal expansion.

Q no: 7(A) What causes a glider to remain air.?

Define latent heat of vaporization. explain it

Define and explain heat capacity

Write a note on linear thermal expansion in solids

Prepare Complete Set Wise Questions For Chapter 8 "9th Class Physics Chapter 8 Long Question Preparation "

Set 1

Set 2

9th Class Physics Chapter 8 Long Question Preparation - Set 1

Q no: 6(A) Explain land and Sea breeze are example of convection.?

Explain the consequences and application of thermal expansion.

Q no 5(A) What is greenhouse effect.Explain the impact of greenhouse it in to Celsius scale and Kelvin scale.

Explain the scales of temperature

Explain the change of state of matter

Explain the consequences and also application of thermal expansion.

Q no: 7(A) What causes a glider to remain air.?

Define latent heat of vaporization. explain it

Define and explain heat capacity

Write a note on linear thermal expansion in solids

9th Class Physics Chapter 8 Long Question Preparation - Set 2

Write a note on linear thermal expansion in solids

Q no 6B) How much heat is required to charge10 g of water °C into of vaporization of water is 2.26 x 106 J kg-¹

Explain the consequences and application of thermal expansion.

Explain the change of state of matter

Explain the scales of temperature

Define specific heat capacity. Give the importance of large heat capacity of water

Q no: 6(A) Explain land and Sea breeze are example of convection.?

Explain the consequences and also application of thermal expansion.

Define latent heat of vaporization. explain it

Q no: 5 (B) How much heat is required to increase the temperature of 0.5 kg of water from 10°C to 65°C.?

9th class Physics Chapter 8 Long Q's (English Medium)

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Q no 6B) How much heat is required to charge10 g of water °C into of vaporization of water is 2.26 x 10⁶ J kg-¹