Thermodynamics Question 13
Question 13 - 30 January - Shift 1
Heat is given to an ideal gas in an isothermal process.
A. Internal energy of the gas will decrease.
B. Internal energy of the gas will increase.
C. Internal energy of the gas will not change.
D. The gas will do positive work.
E. The gas will do negative work.
Choose the correct answer from the options given below:
(1) A and E only
(2) B and D only
(3) C and E only
(4) C and D only
Show Answer
Answer: (4)
Solution:
Formula: First law of thermodynamics
$dQ=dU+dW \Rightarrow dU=nC_v dT$
$dU=0 \quad$ (for isothermal)
$\therefore \quad U=$ constant Also dQ $>0$ (supplied)
Hence $dW>0$
