Introduction to Thermodynamics: Master the Basics of Energy Transfer and Conversion

Question 1

Which type of heat engine has the highest potential efficiency?

Accepted Answer

Carnot engine

Answer

Otto engine

Answer

Diesel engine

Answer

Stirling engine

Question 2

Which thermodynamic property is independent of the path taken to reach a given state?

Accepted Answer

Entropy

Answer

Temperature

Answer

Heat

Answer

Work

Question 3

Which of the following processes is an example of an isothermal change?

Accepted Answer

Boiling water at constant temperature

Answer

Heating a gas in a closed container

Answer

Cooling a liquid in an open beaker

Answer

Adiabatic expansion of a gas

Question 4

According to Boyle's law, how are the pressure and volume of an ideal gas related when temperature is constant?

Accepted Answer

Inversely proportional

Answer

Directly proportional

Answer

Exponentially related

Answer

Logarithmically related

Question 5

Which thermodynamic property describes the degree of disorder or randomness in a system?

Accepted Answer

Entropy

Answer

Temperature

Answer

Energy

Answer

Volume

Question 6

The efficiency of a heat engine is determined by the ratio of:

Accepted Answer

Work output to heat absorbed

Answer

Heat absorbed to heat rejected

Answer

Work input to heat rejected

Answer

Heat rejected to work output

Question 7

Which of the following processes is isobaric?

Accepted Answer

Constant pressure process

Answer

Constant volume process

Answer

Constant temperature process

Answer

Constant entropy process

Question 8

The Gibbs free energy is defined as the difference between:

Accepted Answer

Enthalpy and temperature times entropy

Answer

Internal energy and temperature times entropy

Answer

Enthalpy and pressure times volume

Answer

Internal energy and pressure times volume

Question 9

The Otto cycle is an ideal thermodynamic cycle commonly used in:

Accepted Answer

Internal combustion engines

Answer

Steam turbines

Answer

Refrigeration systems

Answer

Heat pumps

Question 10

Which of the following is NOT a key concept in the first law of thermodynamics?

Accepted Answer

Entropy measures the irreversibility of a process

Answer

Energy can neither be created nor destroyed

Answer

Heat is a form of energy transfer

Answer

Work is a force acting through a distance

Question 11

Which of the following is a closed system in thermodynamics?

Accepted Answer

A pot of boiling water with a lid on

Answer

A piston-cylinder system with a movable piston

Answer

A room with an open window

Answer

A refrigerator with the door open

Question 12

Which of the following is the best description of the second law of thermodynamics?

Accepted Answer

Entropy in an isolated system always increases or stays the same, never decreases

Answer

Energy can neither be created nor destroyed

Answer

Heat always flows from hot to cold objects

Question 13

The first law of thermodynamics states:

Accepted Answer

Energy cannot be created or destroyed, only transferred or transformed

Answer

No heat engine can have an efficiency of 100%

Answer

Entropy always increases in all irreversible processes

Answer

Heat is always lost during energy transfer

Question 14

The change in entropy (ΔS) of a system during an irreversible process is:

Accepted Answer

Greater than or equal to zero

Answer

Independent of the path taken

Answer

Always negative

Answer

Always positive

Question 15

Which of the following is a closed system?

Accepted Answer

A sealed flask containing a gas

Answer

A swimming pool

Answer

A mug of coffee cooling on a table

Answer

A room with an open door

Question 16

The enthalpy (H) of a system is defined as:

Accepted Answer

U + PV

Answer

U - PV

Answer

PV - U

Answer

U/PV

Question 17

Which of the following processes is exothermic?

Accepted Answer

Combustion

Answer

Sublimation

Answer

Vaporization

Answer

Melting

Question 18

Which of the following is a consequence of the second law of thermodynamics?

Accepted Answer

Heat cannot flow spontaneously from a colder to a hotter reservoir

Answer

The universe is constantly expanding

Answer

All processes are reversible

Answer

Entropy always decreases in a closed system