Thermal Properties of Matter

Physics, SSC-Punjab Class 9. This chapter is split into 32 topics and has 786 practice questions. The topics covered are listed below, followed by 10 free sample questions from the chapter.

Topics in this chapter

1. Thermometers and thermometric properties 25 questions
2. Conversion between Fahrenheit and Kelvin 25 questions
3. Structure of a liquid-in-glass thermometer 25 questions
4. Temperature: hotness and coldness 24 questions
5. Absolute zero and molecular motion 26 questions
6. Internal energy of a substance 24 questions
7. Celsius scale 24 questions
8. Exercise review: states of matter and temperature concepts 25 questions
9. Range of a thermometer 24 questions
10. Solids, liquids and gases: particle structure 25 questions
11. Improving sensitivity, range and linearity 21 questions
12. Sensitivity of a thermometer 24 questions
13. Heat and temperature compared 25 questions
14. Liquid-in-glass thermometer: construction and working 27 questions
15. Conversion of Celsius to Fahrenheit 26 questions
16. Conversion of Celsius to Kelvin 26 questions
17. Plasma in nature and technology 22 questions
18. Mercury and alcohol as thermometric liquids 25 questions
19. Linearity of a thermometer 23 questions
20. Fahrenheit scale 24 questions
21. Thermocouple thermometer 25 questions
22. Fixed points: ice point and steam point 25 questions
23. Temperature scales: reasoning and interpolation 25 questions
24. Heat as energy in transit 25 questions
25. Conversion of Fahrenheit to Celsius 26 questions
26. Worked example and exercise numericals on scales 26 questions
27. Kelvin (absolute) scale 23 questions
28. Comparing the three temperature scales 24 questions
29. Conversion of Kelvin to Celsius 24 questions
30. Comparing the states of matter 23 questions
31. Plasma: the fourth state of matter 25 questions
32. Kinetic molecular theory of matter 25 questions

Sample questions: Thermal Properties of Matter

10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.

Q1. If the average kinetic energy of the molecules of a body is high, its temperature is:

• A. high(correct answer)
• B. low
• C. always equal to that of a colder body
• D. zero necessarily

Answer: A.Temperature depends on the average kinetic energy of the molecules, so higher average kinetic energy means higher temperature.

Q2. The kinetic molecular theory explains most of the properties of:

• A. only liquids
• B. solids, liquids and gases(correct answer)
• C. only metals
• D. only gases

Answer: B.The book says most properties of solids, liquids and gases can be explained on the basis of kinetic molecular theory of matter.

Q3. The chapter lists temperature among the basic physical quantities along with:

• A. mass, length and time(correct answer)
• B. speed and acceleration
• C. density and pressure
• D. force, work and power

Answer: A.After standard measuring devices were invented, temperature was included in the list of basic physical quantities like mass, length and time.

Q4. A gas released into a closed room spreads to fill the whole room. This is because gas molecules:

• A. are far apart and have no definite volume or shape(correct answer)
• B. vibrate about fixed positions
• C. slide over each other but stay together in a heap
• D. are held at fixed positions

Answer: A.Gas molecules are relatively far from one another, so the gas has no definite volume or shape and fills the space available.

Q5. If the intermolecular forces in a solid suddenly became very weak, the solid would be expected to:

• A. become denser
• B. stay unchanged
• C. lose its definite shape(correct answer)
• D. become a plasma

Answer: C.Strong forces hold solids in a definite shape; weakening them would allow the molecules to move and the shape would not be maintained.

Q6. 'Lightning streamers' are:

• A. metal rods on buildings
• B. conducting paths through the atmosphere due to ionized air molecules(correct answer)
• C. layers of ice in clouds
• D. patches of frozen air

Answer: B.The book defines them as the conducting paths through the atmosphere due to ionized air molecules, an early stage of lightning.

Q7. Which has smaller degree divisions: Celsius or Fahrenheit?

• A. Cannot be said
• B. Fahrenheit(correct answer)
• C. Both the same
• D. Celsius

Answer: B.The same temperature interval is divided into 180 Fahrenheit degrees but only 100 Celsius degrees, so a Fahrenheit degree is smaller.

Q8. Why can a thermocouple measure very high temperatures where a mercury thermometer cannot?

• A. It contains mercury that boils higher
• B. It has a thicker glass bulb
• C. It uses alcohol
• D. Its metal junction can be heated far beyond the boiling point of mercury(correct answer)

Answer: D.The thermocouple has no liquid to boil; its junction is a small mass of metal (the book says it is useful for very high temperatures).

Q9. If a liquid expands more for each degree rise, the thermometer using it will give:

• A. a smaller movement per degree
• B. no movement
• C. a larger movement of the thread per degree, allowing finer readings(correct answer)
• D. a wider range

Answer: C.Larger expansivity gives a larger thread movement per degree, increasing sensitivity (the book mentions alcohol's larger expansivity for greater accuracy).

Q10. Which of the following would NOT increase the sensitivity of a thermometer?

• A. Using a good conductor like mercury
• B. Making the glass wall of the bulb thicker(correct answer)
• C. Using a small amount of liquid
• D. Using a thin glass wall

Answer: B.The book associates quick response with thin wall, small amount of liquid and good conductor; a thicker wall slows the response.