Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
An ideal gas in a cylinder is compressed adiabatically to one-third of its original volume. A work of $45 \mathrm{~J}$ is done on the gas by the process. The change in internal energy of the gas and the heat flowed into the gas, respectively are
PhysicsThermodynamicsTS EAMCETTS EAMCET 2018 (04 May Shift 2)
Options:
  • A $45 \mathrm{~J}$ and zero
  • B $-45 \mathrm{~J}$ and zero
  • C $45 \mathrm{~J}$ and heat flows out of the gas
  • D $-45 \mathrm{~J}$ and heat flows into the gas
Solution:
1650 Upvotes Verified Answer
The correct answer is: $45 \mathrm{~J}$ and zero
For adiabatic process, $\Delta Q=0$
Now, from first law of thermodynamics, we have
$$
\Delta Q=\Delta U+\Delta W
$$
$\Delta W=-45$ or work is done on the gas.
$$
\begin{array}{lc}
\Rightarrow & 0=\Delta U-45 \\
\Rightarrow & \Delta U=45 \mathrm{~J}
\end{array}
$$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.