MCQs
When a substance is heated, what happens to the motion of its molecules?
A) Speeds up B) Slows down C) No change D) Stops
What particles does plasma consist of?
A) Only atoms B) Only molecules C) Ions or electrons D) Only neutrons
What are the numerical values for the lower and upper fixed points on the Fahrenheit scale?
A) 0 and 100 B) 32 and 212 C) 273 and 373 D) 0 and 273
Why is it incorrect to say that an object contains heat?
A) Heat is only transferred B) Heat is constant C) Heat cannot be measured D) Heat is an illusion
How many fixed temperatures are required to make a temperature scale?
A) One B) Two C) Three D) Four
What is the definition of temperature?
A) The name of an object’s weight B) The name of the intensity of an object’s hotness or coldness C) The name of an object’s length D) The name of an object’s brightness
What basic thermometric property should a suitable material have for making a thermometer?
A) Be a good conductor of heat B) Be a poor conductor of heat C) Change slowly with temperature D) Have non-uniform expansion
At what temperature do the Celsius and Fahrenheit scales have the same numerical value?
A) –40°C B) 40°C C) –45°C D) 0°C
The kinetic theory of particles in matter is related to
A) Only light B) Temperature and heat or internal energy C) Only volume D) Only weight
In what situations is a thermocouple thermometer particularly useful?
A) For very low temperatures B) For very high temperatures or rapidly changing temperatures C) Only for constant temperatures D) Only in laboratories
How was the hotness or coldness of objects initially estimated?
A) By touch B) By sight C) By smell D) By hearing
Which thermometer is most suitable for recording rapidly varying temperatures?
A) Mercury-in-glass clinical thermometer B) Alcohol-in-glass thermometer C) Thermocouple thermometer D) Mercury-in-glass laboratory thermometer
Which physical property is used for temperature measurement?
A) One that varies with change in temperature B) One that remains constant with change in temperature C) One that exists only in solids D) One that exists only in liquids
What energy do molecules have due to their motion?
A) Kinetic energy B) Potential energy C) Thermal energy D) Chemical energy
In what state are the Sun and most other stars?
A) Solid B) Liquid C) Gas D) Plasma
How many states does matter commonly exist in?
A) Two B) Three C) Four D) Five
Temperature is a physical quantity that determines the direction of the flow of
A) Water B) Air C) Thermal energy D) Light
Why should the inner bore of a thermometer be narrow?
A) So that the liquid can expand quickly B) So that the accuracy of measurement is increased C) So that the thermometer is light D) So that less liquid is used
Why is the Kelvin scale used for scientific measurements?
A) It is the oldest scale B) It is the newest scale C) Its zero point represents the complete cessation of molecular motion D) It is the most common scale
How are gas molecules relative to each other?
A) Very close B) Relatively far apart C) Fixed D) Completely bonded
What does the temperature of a substance represent?
A) The total amount of heat contained in it B) The degree of hotness or coldness C) The total number of molecules in it D) The average potential energy of molecules
What is the definition of heat?
A) Energy transferred due to difference in colour between two objects B) Energy that transfers from one object to another due to a difference in temperature between them C) Energy found only in solids D) Energy found only in gases
How do the molecules in a solid behave?
A) Move randomly in all directions B) Rotate and move linearly C) Slide over each other D) Vibrate about their mean positions
What temperature is called absolute zero?
A) 0°C B) 100°C C) Approximately –273°C D) 273°C
What is a characteristic of gas molecules?
A) Has a specific volume B) Has a specific shape C) Has neither a specific volume nor a specific shape D) Vibrate in fixed positions
What fixed points are required for the calibration of thermometers?
A) Boiling point of water B) Ice point and steam point C) Freezing point D) Melting point
When the temperature of an object increases, what happens to its internal energy?
A) Decreases B) Increases C) No change D) First decreases then increases
What is meant by a linear thermometer?
A) It measures equal changes in temperature as equal divisions on the scale B) It measures unequal changes in temperature C) It measures only high temperatures D) It measures only low temperatures
What is the temperature corresponding to the melting point of ice on the Kelvin scale?
A) 0 K B) 273 K C) –273 K D) 32 K
Why does a thermometer have a narrow capillary tube?
A) To measure a large temperature range B) To give a large change for a small temperature rise C) To reduce the amount of liquid needed D) To slow down the response time
On what does the temperature of a substance depend?
A) On the average potential energy of molecules B) On the average kinetic energy of molecules C) On the shape of molecules D) On the number of molecules
What is the kinetic energy of particles at absolute zero?
A) Maximum B) Zero C) Medium D) Minimum
What happens to the intermolecular force as the distance between molecules increases?
A) Increases B) Decreases C) Remains constant D) First decreases then increases
Which property is a better choice for a liquid in a liquid-in-glass thermometer?
A) Wets glass B) Is colourless C) Expands uniformly with temperature D) Is a poor conductor of heat
Why is water not used as a thermometric liquid?
A) It is colourless B) It wets the glass tube C) It expands non-linearly D) It is a good conductor of heat
How strong are intermolecular forces in solids?
A) Very weak B) Weak C) Strong D) Non-existent
What kind of motion can molecules have?
A) Only vibratory B) Only rotational C) Vibratory, rotational and translational D) Only translational
Why are the walls of the thermometer bulb thin?
A) So that heat can quickly pass to the liquid B) So that the thermometer looks good C) So that the amount of liquid can be increased D) So that the chance of breaking is reduced
What is the range of a medical (clinical) thermometer?
A) 0°C to 100°C B) 35°C to 45°C C) –10°C to 110°C D) –273°C to 0°C
How did the discovery of fire affect human life?
A) Increased comfort and convenience B) Increased difficulties C) No significant effect D) Hindered transportation
How strong are intermolecular forces in liquids?
A) Very strong B) Weak enough that they cannot hold molecules in fixed positions C) Medium D) Non-existent
What does the heating process provide to an object?
A) Weight B) Heat or thermal energy C) Shape D) Volume
What does the sensitivity of a thermometer refer to?
A) Detecting large temperature changes B) Detecting even slight changes in an object’s temperature C) Only accurate measurement D) Only determining the range
What was the initial source of light and heat?
A) Fire B) Electricity C) Sun D) Oil
When was temperature included in the list of fundamental physical quantities?
A) After the discovery of fire B) After the invention of standard measuring instruments C) In the modern era D) In ancient times
Why is plasma considered the fourth state of matter?
A) Its properties are completely different from ordinary gas B) It is very cold C) It is very solid D) It cannot conduct current
Mercury is opaque, so why can it be easily seen?
A) Because of its blue colour B) Because of its silvery colour C) Because of its red colour D) Because of its green colour
What is the force of attraction between molecules called?
A) Interatomic force B) Intermolecular force C) Nuclear force D) Gravitational force
What type of motion do the molecules in a gas exhibit?
A) Vibratory motion B) Linear motion C) Random motion D) Rotatory motion
What is the fourth state of matter called?
A) Solid B) Liquid C) Gas D) Plasma
What liquid is commonly used in liquid-in-glass thermometers?
A) Water B) Oil C) Mercury D) Alcohol
For humans, animals and plants, what would be impossible to survive without?
A) Light B) Heat C) Water D) Air
What is heat?
A) The total kinetic energy of the molecules B) The energy in transit due to temperature difference C) The internal energy of a substance D) The work done by molecular motion
What forms in the initial stage of lightning?
A) Solid state B) Plasma state C) Liquid state D) Gas state
What is a disadvantage of using alcohol in a liquid-in-glass thermometer?
A) It is colourless B) It wets the glass tube C) It expands too much D) It has a high boiling point
What are the numerical values for the lower and upper fixed points on the Celsius scale?
A) 0 and 100 B) 32 and 212 C) 273 and 373 D) 0 and 273
What is the sum of the kinetic and potential energies of an object’s molecules called?
A) Heat B) Thermal energy C) Internal energy D) Chemical energy
Short Questions
(i) Mention two ways in which the design of a liquid-in-glass thermometer may be altered to increase its sensitivity.
(ii) What is meant by the temperature of a body?
(iii) What determines the direction of heat flow?
(iv) Explain the statement: “It is not correct to say that an object contains heat.”
(v) With examples, explain how a variable physical property that changes with temperature can be used for temperature measurement.
(vi) When and why was temperature included in the list of fundamental physical quantities like mass, length and time?
(vii) Define temperature and explain how it determines the direction of heat flow when two objects are in thermal contact.
(viii) Describe the properties of solids, liquids and gases on the basis of molecular theory.
(ix) Explain the sensitivity, range and linearity of thermometers.
(x) Is the kinetic molecular theory of matter applicable to the plasma state of matter? Describe briefly.
(xi) What basic thermometric properties should a suitable material possess for making a thermometer?
(xii) What is the importance of fixed points for making a temperature scale?
(xiii) There are various objects made of cotton, wood, plastic, metals, etc., on a winter night. Compare their temperatures with the air temperature by touching them with your hand.
(xiv) Distinguish between heat and internal energy.
(xv) What do “Lowest temperature obtained for He” and “Lowest temperature for electrons in a metal” mean?
(xvi) Comment on the statement: “A thermometer measures its own temperature.”
(xvii) Give natural examples of the presence of plasma.
(xviii) How does plasma differ from gas?
(xix) When you touch a cold surface, does cold travel from the surface to your hand, or does energy travel from your hand to the cold surface?
(xx) Describe the construction and function of a thermocouple thermometer. In what situations is it more useful?
(xxi) Explain the particulate structure of solids, liquids and gases in relation to intermolecular forces and distances.
(xxii) Comment on the statement: “A hot body does not contain heat.”
(xxiii) What do you mean by the linearity of a thermometer?
(xxiv) Why are there no negative numbers on the Kelvin scale?
(xxv) What makes the scale reading of a thermometer accurate?
(xxvi) How did the discovery of fire greatly increase the comfort and conveniences of mankind?
(xxvii) What is the relationship between particle motion and temperature? Explain absolute zero.
(xxviii) Why should the inner bore of the thermometer be narrow?
(xxix) What is a thermometer and on what principle does it work?
(xxx) Discuss whether the Sun is matter.
(xxxi) Why was initially touching objects to estimate their hotness or coldness not a good criterion for judging the intensity of hotness?
(xxxii) Comment on the sensitivity, range and linearity of a thermocouple thermometer.
(xxxiii) Describe the construction and working principle of a liquid-in-glass thermometer.
(xxxiv) Why do solids have a fixed volume and shape according to the particle theory of matter?
(xxxv) Why is plasma considered the fourth state of matter? Explain with examples.
(xxxvi) Describe the Celsius, Fahrenheit and Kelvin scales and state their fixed points.
(xxxvii) Does it make sense to talk about the temperature of a vacuum?
(xxxviii) Why would you not expect all the molecules in a gas to have the same speed?
(xxxix) Why is water not suitable for use in thermometers? Without calculations, guess the equivalent temperature of 373 K on the Celsius and Fahrenheit scales.
(xl) What is the relationship between the motion of molecules and their energy?
(xli) Why is mercury usually preferred to alcohol as a thermometric liquid?
(xlii) What is the effect of raising the temperature of a liquid?
(xliii) What is the range of temperatures for different bodies?
(xliv) What is the main objective of the chapter on Thermal Properties of Matter?
(xlv) Compare the spacing of molecules in the solid, liquid and gaseous states.
(xlvi) Why are fixed points necessary in the calibration of thermometers? What do the ice point and steam point mean?
(xlvii) Define heat as ‘energy in transit’.
(xlviii) Differentiate between the construction and function of liquid-in-glass and thermocouple thermometers.
(xlix) One litre of water is heated by a stove and its temperature rises by 2°C. If two litres of water are heated on the same stove for the same time, what will be the rise in temperature?
(l) Can you feel your fever by touching your own forehead? Explain.
(li) Define heat and clarify its difference from internal energy.
(lii) State how increasing the temperature of an object increases its internal energy.
(liii) What are the reasons that gases have neither a fixed volume nor a fixed shape?
(liv) What is absolute zero and what is its value?
(lv) How does the construction of a liquid-in-glass thermometer affect its sensitivity, range and linearity?
(lvi) What is meant by the thermometric property of a substance? Describe some thermometric properties.
(lvii) Introduce the molecular kinetic theory of matter and state its basic principles.
(lviii) Describe the main scales used for the measurement of temperature. How are they related to each other?
(lix) State the advantages and disadvantages of choosing mercury and alcohol as thermometric liquids.
(lx) What is meant by the sensitivity of a thermometer?
(lxi) Why are the walls of the thermometer bulb thin?
(lxii) Which is greater: an increase in temperature of 1°C or one of 1°F?
(lxiii) Why have heat and thermal energy always been a necessity for humans, animals and plants in this world?
Long Questions
Describe the main points of the particle theory of matter that differentiate solids, liquids and gases.
Convert 5°F to Celsius and Kelvin scale.
Explain the difference between heat and temperature with examples.
What is meant by sensitivity, range and linearity of thermometers? Explain with examples.
What is temperature? How is it measured? Describe briefly the construction of a mercury-in-glass thermometer.
Explain the importance of fixed points in thermometers and describe three common temperature scales.
Mercury expands by 0.2 cm when heated from 20°C to 80°C in a thermometer. Find the expansion per degree Celsius.
The ice and steam points on an ungraduated thermometer are found to be 192 mm apart. What temperature will be on the Celsius scale if the length of the mercury thread is 67.2 mm above the ice point mark?
A thermocouple thermometer shows a potential difference of 15 mV at a junction. If the calibration gives 1 mV = 5°C, find the temperature.
Describe the main points of the particle theory of matter which differentiate solids, liquids and gases.
If the absolute temperature of a gas is 200 K, what is its temperature in Celsius and Fahrenheit?
Compare mercury and alcohol thermometers based on properties and uses.
A metal rod is heated from 25°C to 150°C. Find the change in its length if its expansion coefficient is 0.000012 per degree Celsius and its original length is 100 cm.
A thermometer reads 40°C. What will be its reading in Fahrenheit and Kelvin?
Convert 77°F to Celsius and Kelvin.
Discuss the relationship between temperature and the kinetic energy of molecules.
Convert 5°F to Celsius and Kelvin scale.
Define plasma and explain its properties with examples.
Convert the following temperatures:
(a) 50°C to Fahrenheit
(b) –10°C to Fahrenheit and Kelvin
(c) 98.6°F to Celsius and Kelvin
Describe the construction and working of a liquid-in-glass thermometer.
What is the equivalent temperature of 25°C on Fahrenheit and Kelvin scales?
Compare the three scales used for measuring temperature.
At what temperature are Celsius and Fahrenheit thermometer readings the same?
What is temperature? How is it measured? Describe briefly the construction of a mercury-in-glass thermometer.
The temperature of a furnace is 1000 K. Convert it to Celsius and Fahrenheit.
What are sensitivity, range and linearity in thermometers? Explain each in detail.
The length between the fixed points of a liquid-in-glass thermometer is 20 cm. If the mercury level is 4.5 cm above the lower mark, what is the temperature on the Fahrenheit scale?
Compare the three scales used for measuring temperature.
Explain the kinetic molecular theory of matter in detail.
What is meant by sensitivity, range and linearity of thermometers? Explain with examples.
The ice and steam points on an ungraduated thermometer are found to be 192 mm apart. What temperature will be on the Celsius scale if the length of the mercury thread is 67.2 mm above the ice point mark?
Explain how a thermocouple thermometer works and why it is useful.
The temperature of a hot iron rod is 400 K. Convert it to Celsius and Fahrenheit.
Convert 30°C to Fahrenheit and Kelvin.
The temperature of a normal human body on the Fahrenheit scale is 98.6°F. Convert it into Celsius scale and Kelvin scale.
What is the equivalent temperature of 25°C on Fahrenheit and Kelvin scales?
The temperature of a normal human body on the Fahrenheit scale is 98.6°F. Convert it into Celsius scale and Kelvin scale.
At what temperature are Celsius and Fahrenheit thermometer readings the same?
A scientist measures a temperature of 450 K in an experiment. Convert it to Celsius and Fahrenheit.
The length between the fixed points of a liquid-in-glass thermometer is 20 cm. If the mercury level is 4.5 cm above the lower mark, what is the temperature on the Fahrenheit scale?