Thermal Physics Quizzes for Sixth Form Physics

Question 1

Which of the following is **not** a fundamental mode of heat transfer?

Accepted Answer

Evaporation

Answer

Conduction

Answer

Convection

Answer

Radiation

Question 2

A power plant has an efficiency of 40%. What happens to the remaining energy that is not converted into electricity?

Accepted Answer

It is released as waste heat.

Answer

It is stored in the generator.

Answer

It is used to power the plant's systems.

Question 3

How does the average kinetic energy of gas molecules relate to the temperature of the gas? Explain how this relationship affects the behavior of gases at different temperatures.

Accepted Answer

The average kinetic energy of gas molecules is directly proportional to the absolute temperature of the gas.

Answer

The average kinetic energy of gas molecules is inversely proportional to the temperature of the gas in degrees Celsius.

Answer

The average kinetic energy of gas molecules is independent of the temperature of the gas.

Question 4

Explain radiative heat transfer and describe how the rate of radiative heat transfer is affected by various factors.

Accepted Answer

Radiation heat transfer occurs due to temperature differences between objects, with heat flowing from the hotter to the colder object via electromagnetic waves.

Answer

Radiation heat transfer occurs only when objects are physically touching.

Answer

The rate of radiative heat transfer is not affected by the emissivity of the surfaces.

Answer

The rate of radiative heat transfer is not affected by the distance between the surfaces.

Question 5

Which material is better for constructing a heat exchanger: copper or rubber? Explain your answer based on the difference in their thermal conductivities.

Accepted Answer

Copper is better because it has a higher thermal conductivity.

Answer

Rubber is better because it has a higher thermal conductivity.

Answer

The thermal conductivity of the material does not affect the performance of a heat exchanger.

Answer

Copper and rubber have the same thermal conductivity, so the choice of material does not matter.

Question 6

Which of the following statements accurately describes the first law of thermodynamics as it applies to a closed system?

Accepted Answer

The total energy within the system remains constant over time.

Answer

Entropy within the system inevitably decreases over time.

Answer

If heat is added to the system, its temperature will invariably rise.

Question 7

The specific heat capacity of a material is defined as the quantity of heat energy needed to increase the temperature of 1 kilogram of that material by one degree Celsius.

Accepted Answer

True

Answer

False

Answer

1 mole of the substance

Answer

1 cubic metre of the substance

Question 8

A heat engine operates between reservoirs at temperatures T1 and T2. Which of the following represents the efficiency of the heat engine?

Accepted Answer

(T1 - T2) / (T1 + T2)

Answer

T1 - T2 / T1

Answer

T1 + T2 / T1

Answer

(T1 + T2) / (T1 - T2)

Question 9

The thermal conductivity of a material measures its capacity to:

Accepted Answer

Transfer heat through conduction

Answer

Absorb heat radiation

Answer

Reflect heat energy

Answer

Store thermal energy

Question 10

Which of the following is the International System of Units (SI) unit of temperature?

Accepted Answer

Kelvin

Answer

Fahrenheit

Answer

Celsius

Answer

Rankine

Question 11

A material with a higher specific heat capacity requires:

Accepted Answer

More energy to raise its temperature by 1°C

Answer

Less energy to raise its temperature by 1°C

Answer

The same amount of energy to raise its temperature by 1°C

Answer

No energy to raise its temperature by 1°C

Question 12

Which of the following is NOT a law of thermodynamics?

Accepted Answer

The efficiency of a heat engine can exceed 100%.

Answer

The entropy of an isolated system increases over time.

Answer

Energy cannot be created or destroyed, only transferred or transformed.

Answer

Heat always flows from a hotter object to a colder object.

Question 13

The efficiency of a heat engine is defined as:

Accepted Answer

The ratio of the work output to the heat input

Answer

The ratio of the heat output to the work input

Answer

The ratio of the work input to the heat output

Answer

The ratio of the heat input to the work output

Question 14

The greenhouse effect is primarily caused by:

Accepted Answer

The accumulation of certain gases in the atmosphere that trap heat

Answer

The reflection of sunlight back into space

Answer

The absorption of heat by the oceans

Answer

The burning of fossil fuels

Question 15

According to the kinetic theory of gases, how do gas molecules behave?

Accepted Answer

Tiny spherical particles moving randomly in various directions

Answer

Possessing a specific shape and volume

Answer

Composed of positively and negatively charged particles

Answer

Perfectly elastic spheres constantly colliding with each other

Question 16

The root mean square (RMS) speed of gas molecules represents:

Accepted Answer

The square root of the mean of squared speeds of all gas molecules

Answer

The average speed of all gas molecules

Answer

The speed at which most gas molecules move

Answer

The velocity of the fastest gas molecule

Question 17

How does temperature relate to the average kinetic energy of gas molecules?

Accepted Answer

Directly proportional

Answer

Inversely proportional

Answer

No relationship exists

Answer

Average kinetic energy is independent of temperature

Question 18

State which of the following correctly defines an isothermal process?

Accepted Answer

Temperature remains constant throughout the process.

Answer

Pressure remains constant throughout the process.

Answer

Volume remains constant throughout the process.

Answer

Heat transfer does not occur during the process.

Question 19

The efficiency of a heat engine is defined as:

Accepted Answer

The ratio of output work to input heat energy

Answer

The ratio of input heat energy to output work

Answer

The difference between input and output energy

Answer

The sum of input and output energy

Question 20

The Carnot efficiency represents:

Accepted Answer

The highest possible efficiency of any heat engine

Answer

The actual efficiency of a Carnot cycle engine

Answer

The efficiency of a real-world heat engine

Answer

The ratio of input to output heat energy

Question 21

Specific heat capacity is defined as the amount of heat required to raise the temperature of:

Accepted Answer

1 kg of a substance by 1 °C

Answer

1 g of a substance by 1 °C

Answer

1 L of a substance by 1 °C

Answer

1 m of a substance by 1 °C

Question 22

According to the first law of thermodynamics, which of the following statements is true?

Accepted Answer

The total amount of energy in an isolated system remains constant.

Answer

Energy can be created or destroyed.

Answer

Entropy always increases.

Answer

Heat flows from cold to hot.

Question 23

The root mean square speed of gas molecules is directly proportional to:

Accepted Answer

The square root of the absolute temperature

Answer

The absolute temperature

Answer

The pressure

Answer

The volume

Question 24

Which of the following gases is a major contributor to the greenhouse effect?

Accepted Answer

Carbon dioxide

Answer

Oxygen

Answer

Nitrogen

Answer

Argon

Question 25

Thermal conductivity is defined as:

Accepted Answer

The rate of heat flow through a material

Answer

The amount of heat required to raise the temperature of a material by 1 °C

Answer

The specific heat capacity of a material

Answer

The density of a material

Question 26

Which of the following materials is a good conductor of heat?

Accepted Answer

Copper

Answer

Wood

Answer

Styrofoam

Answer

Air

Question 27

Entropy is a measure of:

Accepted Answer

The disorder of a system

Answer

The energy of a system

Answer

The temperature of a system

Answer

The volume of a system

Question 28

Identify the SI unit used to quantify thermal energy:

Accepted Answer

Joule

Answer

Calorie

Answer

British Thermal Unit

Answer

Kilowatt-hour

Question 29

The specific heat capacity of a substance is defined as the amount of thermal energy required to elevate the temperature of 1 kg of that substance by:

Accepted Answer

1 °C

Answer

1 K

Answer

1 J

Answer

1 cal

Question 30

The first law of thermodynamics establishes that the total energy of an isolated system:

Accepted Answer

Remains constant

Answer

Becomes zero

Answer

Decreases continuously

Answer

Increases continuously

Question 31

The root mean square speed of gas molecules:

Accepted Answer

Is directly proportional to the square root of absolute temperature.

Answer

Is inversely proportional to the square root of absolute temperature.

Answer

Has no relation to the absolute temperature.

Answer

Cannot be determined from the given information.

Question 32

Which of the following is an adiabatic process?

Accepted Answer

A process where there is no heat transfer between the system and its surroundings.

Answer

A process where the temperature of the system remains constant.

Answer

A process where the volume of the system remains constant.

Answer

A process where the pressure of the system remains constant.

Question 33

Which of the following is NOT a unit of thermal energy?

Accepted Answer

Kelvin

Answer

Joule

Answer

Calorie

Answer

British Thermal Unit (BTU)

Question 34

According to the first law of thermodynamics, energy can be:

Accepted Answer

Transferred or transformed.

Answer

Created or destroyed.

Answer

Released only from chemical reactions.

Answer

Absorbed only by liquids.

Question 35

The third law of thermodynamics states that:

Accepted Answer

The entropy of a perfect crystal is zero at absolute zero.

Answer

The entropy of a gas increases as the volume increases.

Answer

Heat cannot flow spontaneously from a colder to a hotter body.

Answer

The specific heat capacity of a substance is constant.

Question 36

The pressure exerted by a gas is primarily due to:

Accepted Answer

Collisions of its molecules with the walls of its container

Answer

The weight of its molecules

Answer

The gravitational force acting on its molecules

Answer

The temperature of the container

Question 37

In the International System of Units (SI), the unit of heat capacity is:

Accepted Answer

Joule per gram per degree Celsius

Answer

Watt

Answer

Celsius

Answer

Kelvin

Question 38

The specific heat capacity of a substance is defined as the amount of heat energy required to raise the temperature of 1 gram of that substance by:

Accepted Answer

1 degree Celsius

Answer

10 degrees Celsius

Answer

100 degrees Celsius

Answer

1 Joule

Question 39

Which of the following statements is NOT a consequence of the First Law of Thermodynamics?

Accepted Answer

Heat can spontaneously flow from a colder to a hotter body.

Answer

Energy can neither be created nor destroyed during a thermodynamic process.

Answer

The change in internal energy of a system is equal to the heat added to the system minus the work done by the system.

Answer

Entropy always increases during an irreversible process.

Question 40

An isothermal process in thermodynamics is characterized by:

Accepted Answer

Constant temperature

Answer

Constant pressure

Answer

Constant volume

Answer

Constant heat flow

Question 41

The absolute zero of temperature on the Kelvin scale is approximately equal to:

Accepted Answer

-273.15 degrees Celsius

Answer

0 degrees Celsius

Answer

100 degrees Celsius

Answer

273.15 degrees Celsius

Question 42

The average kinetic energy of molecules in a gas is directly proportional to:

Accepted Answer

Temperature

Answer

Pressure

Answer

Volume

Answer

Mass

Question 43

Which definition best describes specific heat capacity?

Accepted Answer

The amount of energy needed to raise the temperature of 1 kg of a substance by 1 K

Answer

The amount of energy needed to raise the temperature of 1 g of a substance by 1 K

Answer

The amount of energy needed to raise the temperature of 1 mole of a substance by 1 K

Answer

The amount of energy needed to raise the temperature of 1 cm³ of a substance by 1 K

Question 44

Which of the following is the SI unit for thermal conductivity?

Accepted Answer

W/(m·K)

Answer

J/(kg·K)

Answer

cal/(g·°C)

Answer

K/(W·m)

Question 45

Which law of thermodynamics states that the total entropy of an isolated system can never decrease?

Accepted Answer

Second law

Answer

First law

Answer

Third law

Answer

Zeroth law

Question 46

For an object placed in a vacuum chamber and heated to a high temperature, what is the primary mode of heat transfer from the object?

Accepted Answer

Radiation

Answer

Convection

Answer

Conduction

Answer

Evaporation

Question 47

Which of the following materials has the highest thermal conductivity?

Accepted Answer

Copper

Answer

Wood

Answer

Water

Answer

Air

Question 48

What is a characteristic feature of a black body?

Accepted Answer

It absorbs all incident radiation

Answer

It reflects all incident radiation

Answer

It transmits all incident radiation

Answer

It scatters all incident radiation

Question 49

The SI unit of specific heat capacity is:

Accepted Answer

(A) Joule per kilogram Kelvin

Answer

(B) Joule

Answer

(C) Kelvin

Answer

(D) Joule per Kelvin

Question 50

The zeroth law of thermodynamics states that:

Accepted Answer

(A) If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other.

Answer

(B) The entropy of an isolated system always increases.

Answer

(C) Heat flows from a hotter object to a colder object.

Answer

(D) The pressure of a gas is directly proportional to its temperature.

Question 51

Which of the following is a greenhouse gas?

Accepted Answer

(C) Carbon dioxide

Answer

(A) Nitrogen

Answer

(B) Oxygen

Answer

(D) Hydrogen

Question 52

Which of the following is not a Maxwell-Boltzmann distribution?

Accepted Answer

(B) A uniform distribution

Answer

(A) A Gaussian distribution

Answer

(C) A normal distribution

Answer

(D) A Poisson distribution

Question 53

The average kinetic energy of molecules is directly proportional to:

Accepted Answer

(A) Temperature

Answer

(B) Pressure

Answer

(C) Volume

Answer

(D) Mass

Question 54

What is the average kinetic energy of an ideal gas molecule at a given temperature?

Accepted Answer

(3/2)kT

Answer

(1/2)kT

Answer

kT

Answer

2kT

Question 55

What is the efficiency of a heat engine?

Accepted Answer

The ratio of the work output to the heat input.

Answer

The ratio of the heat input to the work output.

Answer

The ratio of the heat output to the heat input.

Answer

The ratio of the work input to the heat output.

Question 56

Convert the following temperature from Celsius to Fahrenheit: 20°C

Accepted Answer

68°F

Answer

32°F

Answer

104°F

Answer

212°F

Question 57

In a gas-filled cylinder with a piston, if the volume is doubled while the temperature remains constant, what happens to the pressure?

Accepted Answer

Halves

Answer

Doubles

Answer

Stays the same

Answer

Increases fourfold

Question 58

Which material is a good conductor of heat?

Accepted Answer

Copper

Answer

Wood

Answer

Glass

Answer

Cotton

Question 59

The temperature of a gas is directly proportional to its:

Accepted Answer

Kinetic energy

Answer

Volume

Answer

Pressure

Answer

Density

Question 60

Which of the following is a unit of energy?

Accepted Answer

Joule

Answer

Newton

Answer

Watt

Answer

Kelvin

Question 61

In a power plant with an efficiency of 40%, what happens to the remaining 60% of energy that is not converted into electricity?

Accepted Answer

It is released as waste heat into the environment.

Answer

It is stored as potential energy within the fuel.

Answer

It is emitted as electromagnetic radiation.

Answer

It is converted into chemical energy and stored in batteries.

Question 62

What is specific heat capacity? How does it affect the amount of heat energy needed to raise the temperature of a certain mass of a substance?

Accepted Answer

Specific heat capacity is the amount of heat energy needed to raise the temperature of one kilogram of a substance by one degree Celsius.

Answer

Specific heat capacity is the ratio of a substance's temperature to its mass.

Answer

Specific heat capacity is the amount of heat needed to melt one kilogram of a substance.

Answer

Specific heat capacity is the same for all substances.

Question 63

Which of the following is the SI unit of temperature?

Accepted Answer

Kelvin

Answer

Degrees Celsius

Answer

Degrees Fahrenheit

Answer

Degrees Rankine

Question 64

Which of the following processes is exothermic?

Accepted Answer

Combustion of fuel

Answer

Melting of ice

Answer

Evaporation of water

Answer

Condensation of steam