Which of the following is the statement of the first law of thermodynamics?
a) Energy can be created
b) Energy is always conserved in a system
c) Heat and work are unrelated
d) Heat cannot be converted into work
What does the first law of thermodynamics state about energy in an isolated system?
a) Energy can be destroyed
b) Energy is always constant
c) Energy can be transferred but never created or destroyed
d) Energy increases over time
The change in internal energy of a system is equal to:
a) The heat added to the system
b) The work done by the system
c) The sum of the heat added to the system and the work done by the system
d) The temperature of the system
The first law of thermodynamics is essentially a statement of the:
a) Conservation of mass
b) Conservation of energy
c) Conservation of momentum
d) Conservation of temperature
In the equation ΔU = Q – W, what does ΔU represent?
a) The change in pressure of the system
b) The change in internal energy of the system
c) The work done by the system
d) The heat transferred to the system
What does the “Q” in the first law equation represent?
a) Work done by the system
b) Temperature of the system
c) Heat added to the system
d) Internal energy of the system
What does the “W” in the first law equation represent?
a) Heat added to the system
b) Work done by the system
c) Change in internal energy
d) Temperature change
Which of the following is true about the first law of thermodynamics?
a) It only applies to closed systems
b) It applies to both closed and open systems
c) It implies that heat cannot be converted to work
d) It requires the conservation of mass
In an isothermal process, the change in internal energy of the system is:
a) Zero
b) Positive
c) Negative
d) Dependent on the amount of heat added
If a gas expands and does work, the work done is:
a) Negative
b) Positive
c) Zero
d) Infinite
Which of the following processes involves the transfer of heat without doing work?
a) Isobaric process
b) Isochoric process
c) Isothermal process
d) Adiabatic process
During an adiabatic process, there is:
a) No heat exchange with the surroundings
b) No work done by the system
c) A constant temperature
d) A constant pressure
In the first law of thermodynamics, when the system does work on the surroundings, the internal energy of the system:
a) Increases
b) Decreases
c) Remains constant
d) Is unaffected by work done
In an isobaric process, the heat added to the system does work by:
a) Changing the pressure
b) Changing the temperature
c) Changing the volume
d) Changing the internal energy
In a cyclic process, the total change in internal energy of the system is:
a) Zero
b) Equal to the heat added
c) Equal to the work done by the system
d) Dependent on the type of process
The work done by a gas in an expansion can be calculated by the formula:
a) W = P × ΔV
b) W = ΔU × P
c) W = Q × ΔV
d) W = ΔV × T
If a system absorbs heat and no work is done, the change in internal energy is equal to:
a) The heat absorbed
b) The work done
c) The temperature change
d) Zero
If a system does 100 J of work and absorbs 200 J of heat, what is the change in internal energy?
a) 100 J
b) 200 J
c) 300 J
d) 400 J
When work is done on a system, the internal energy of the system:
a) Increases
b) Decreases
c) Remains constant
d) Becomes zero
The internal energy of an ideal gas depends only on:
a) The temperature
b) The pressure
c) The volume
d) The work done
Which of the following is true for a closed system under the first law of thermodynamics?
a) The total heat energy remains constant
b) The system can exchange both heat and work with its surroundings
c) Work is always done by the system
d) The change in internal energy is zero
In a reversible process, the first law of thermodynamics implies that:
a) The change in internal energy is zero
b) The work done is always positive
c) The heat absorbed equals the work done
d) The total energy change is reversible
If a system undergoes a process where both work and heat are exchanged, the first law tells us that:
a) The work done by the system equals the heat absorbed
b) The work done by the system equals the change in internal energy
c) The change in internal energy equals the sum of the work and heat
d) The heat absorbed is independent of the work done
In an isothermal expansion of an ideal gas, the change in internal energy is:
a) Positive
b) Negative
c) Zero
d) Dependent on the volume change
During an adiabatic compression, the temperature of the system:
a) Remains constant
b) Increases
c) Decreases
d) Depends on the volume change
Which of the following is true for a process where no heat is exchanged (adiabatic process)?
a) Q = 0
b) W = 0
c) ΔU = 0
d) P × V = constant
In a cyclic process, the heat added to the system is equal to:
a) The work done by the system
b) The work done on the system
c) The change in internal energy
d) The heat rejected by the system
Which of the following is an example of a system undergoing an isothermal process?
a) A gas expanding in a vacuum
b) A gas in a piston at constant temperature
c) A gas undergoing adiabatic compression
d) A gas in a piston at constant pressure
