Examveda

A gas performs the maximum work, when it expands

A. Non-uniformly

B. Adiabatically

C. Isobarically

D. Isothermally

Answer: Option C

Solution (By Examveda Team)

The Isobaric, isothermal and adiabatic process represented in $$P – V$$ as the following.
Since, area under $$P-V$$   plot for isobaric process is more than the isothermal and adiabatic process the work done in isobaric process is highest.

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Comments (1)

  1. Atanu Chatterjee
    Atanu Chatterjee:
    6 months ago

    To determine when a gas performs maximum work during expansion, let’s evaluate each process:

    πŸ”Ή A. Non-uniformly
    Usually implies irreversible or uncontrolled process.

    Irreversible processes do not give maximum work.
    ❌ Incorrect

    πŸ”Ή B. Adiabatically
    No heat exchange.

    Work is done at the expense of internal energy.

    Compared to isothermal expansion, less work is done for the same volume change.
    ❌ Incorrect

    πŸ”Ή C. Isobarically (constant pressure)
    Work =
    π‘Š
    =
    𝑃
    (
    𝑉
    2
    βˆ’
    𝑉
    1
    )
    W=P(V
    2
    ​
    βˆ’V
    1
    ​
    )

    Less work than isothermal expansion for an ideal gas under similar conditions.
    ❌ Incorrect

    πŸ”Ή D. Isothermally (constant temperature)
    For ideal gases, reversible isothermal expansion gives:

    π‘Š
    =
    𝑛
    𝑅
    𝑇
    ln
    ⁑
    (
    𝑉
    2
    𝑉
    1
    )
    W=nRTln(
    V
    1
    ​

    V
    2
    ​

    ​
    )
    This is the maximum possible work a gas can do between two volumes, since heat continuously enters to keep temperature constant and support expansion.

    βœ… Correct answer: D. Isothermally

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